One thing that always annoyed me is that whenever Sims with vastly different skintones have kids (example a Sim with dark blue skin, and a Sim with light red skin), their kids never have a skin that's in the middle of the value range. Essentially it's impossible for mixed race Sims to exist. For some reason they always come out either matching Parent 1 with dark blue skin, or Parent 2 with light red skin. Sometimes they'll combine a little and have the value range of Parent 1 and skin ramp of Parent 2 to create a Sim with dark red skin, or vice-versa, but never any medium reds or blues.

NRAAS Story Progression and all its modules fixes this slightly because now my Sim children will have the skin ramp slider move slightly, but it's still a very insignificant movement across the skin ramp. It's barely noticeable. Is there any setting within NRAAS Story Progression so I can make the skin blending of the parents more intense or frequent? Or is there any other mod that produces even more skin blending?

Also, this isn't a one time thing. I've started a bunch of testing saves for the sole purpose of making Sims have children and then comparing their skintone to their parents and most of the time, if they don't completely take one parent's skintone, the value range only ever so slightly moves to the left or right, but never by much.

I've attached an example below, where the child is slightly lighter than her dad, but the skin ramp value still barely moved. Her mom's skin uses the default EA red undertone skin and its value is set as low as it can be, meanwhile she and her dad use the EA neutral undertone skin.

I'm not sure why some have an issue with this but it's not impossible to have blended skin tones in the game as is. This screenshot below is without any mods except NRass NoCD, pose player and some poses, and base game only.


And even in my modded game, I don't use any mods that would change anything genetically concerning skin tones.


However from what I observed, it seems there is more to a Sim when it comes to genetics. Meaning that some Sims have "dominant/expressed genes" which mostly, if not every single time carry over to their child(ren). Some Sims have "recessive/unexpressed genes" which means while it may pass down to their child(ren) it won't be seen on said child(ren) and may come about a different generation; or it shows up in their child(ren) occasionally. And then there are some Sims who both have dominant genes or both have recessive genes and in this case is when there is a high chance for blending and/or a mixture of both parents genes. Just take a look at real life photos of multi-ethnic people and their parents/family. Not everyone "looks" multi-ethnic but they are. While some display a combination of both parents and/or previous family members genes doesn't set a standard for how a multi-ethnic person is supposed to look like. TS3 is quite reminiscent of reality in that way. Also take Miles Morales for example, he's multi-ethnic though he doesn't look it.
https://www.youtube.com/watch?v=gWMvHJdC4eM

I think the issue arises because some players keep having dominant/recessive pairings.

So yes, some Sim couples don't blend skin tones. Though the father does have a custom skin, I doubt that has much, if any, effect.

My understanding is that both the game (EA) and Nraas, take each feature from each parent and apply to child. Mom's or dad's nose, eyes, chin, ears, skin tone, various sliders, etc etc etc... They do not "blend" them, unfortunately, as far as I know. I remember someone mentioning a Sims genetics mod, but do not recall the name or where it is.

I will sometimes use Nraas MC advanced "play with genetics", but that still only does one parent's skin tone.

When I was researching how genetics went in TS3, I actually came across your forum post from a few years ago! (https://forums.thesims.com/en_us/di...s-in-the-sims-3)

In your first family photo (the ones with grayish green skin), do they all use the same skin tone ramp? Like, is the little dot under the skins tab all the same one? Because in the second family, it looks like they’re all using EA’s yellow undertoned skin, and from what I recall, skins do actually blend if the parent Sims use the same skin tone ramp. At least according to post 12 here (https://modthesims.info/t/391106).

That would also explain why the third family experiences no skin blending, as the father presumably uses an Asian skin that’s a separate skin tone ramp to the mother’s EA skin.

So in essence, is there any mod that blends skins coming from two different skin tone ramps?

Oh, okay so what exactly is Nraas’s genetic skin blending then? Is it just that in a default EA game, when parents have different skin ramps, a child will inherit both the skin ramp, and also the value/shade of it, whereas in NRaas, a child will inherit one parent’s skin ramp, and possibly the other’s skin tone value?

I also use the MC “Play With Genetics” and it’s odd because using that system, my sims actually [I]will[I] experience skin blending, even if the parents have different ramps, same with the “Play With Genetics” option directly out of CAS. It’s just that when sims are born in game, the skin blending for different ramps stops.

I just would prefer a way to do it without MC’s “Play With Genetics” since you can’t select the genetics of a dead sim. In a few of my saves, my sims have children but their partner is dead, so I can’t really select their deceased parent to use their genes in MC’s “Play With Genetics”. Ghosts never appear in the selection option for some reason.

Also, I think the mod you’re thinking of is this one (https://modthesims.info/showthread.php?t=663498)

Yeah I had that issue too. I fixed it by downloading the random genetics mod, but now the issue is in fixing the skin tones lol

Update: Skins from different skin tone ramps are now sometimes blending correctly. I have no idea what caused this, and I’ve made no changes to any mods I have. The only random weirdness I noticed is that one baby came out with a nice blend, but then a few moments later, her skin had darkened to be exactly her mother’s. Again, don’t know what caused this.

Maybe my sample size was too small? Even then, before now, I tested over 20 births with various families and saves and none of their skins blended too much so I feel like it can’t just be a sample size that was too small.

So yeah, idk lol

No idea. I did not post that. ))) But yes, I did fall short regarding that if the parents use the same tone ramp, and one is darker than the other, children will receive skin tones somewhere along that same tone ramp.



Not sure how that would be. A parent with a red tone and one with blue tone does not make a purple baby. At least, I have never seen this. I guess it might be possible if the folks at Nraas set their minds to it? Just coding numbers that correspond to colors, I imagine... but for EA to bother with it??? The post by @simsample may be the mod, but I did not download it to check. Never used it, as I have been okay with "play with genetics and/or tweaking the Sim in CAS.



One parent may be dominant, but it seems that even basic EA genetics does combine features. Nose from one, eyes from the other, stuff like that, but not one parent with Asian style eyes, other with round eyes, and child being in the middle. THAT does not seem to happen.

In the red/blue example, I was originally hoping for something like Parent 1 is dark red, Parent 2 is light blue, kids can be anywhere from dark red to light red, or dark blue to light blue. Inheriting one skin ramp and then a blending of the skin values.

And yeah, the feature blending doesn’t happen on its own, but using the Random Genetics mod, it actually implements that!

Whatever the case, my sims skin tones have started blending and creating values in the middle, regardless of if the parents use different skin ramps. So I guess if anyone else ever has the issue, I’m using NRAAS Story Progression and all its modules, and in the General Pregnancy Options, I have turned of Advanced Genetics (I’m worried it’ll conflict with the Random Genetics Mod), and turned on Genetic Skin Blending (to allow for parents of different skin ramps to have kids with tones that are in between). I also use this random genetics mod to get rid of facial clones of parents and blend facial features (https://www.reddit.com/r/Sims3/comm...eb2x&context=3).

I’ve also attached an image showing that genetic skin blending now randomly works for me. Sorry about all the posts everyone lol.

I have advanced genetics and skin blending on in Story Progression, but that does not blend 2 different color ramps.

I may look into that other mod you linked, but how does it change other facial appearances?

If I remember correctly, the first family (black and white) they both are the same skin tone ramp but the opposites of each end. However, you skipped the other family I showed you with most of their children having blended skin tones. They have two different skin tone ramps, therefore it is possible without mods.

Trinity's Skin Tone Ramp


Nathaniel's Skin Tone Ramp


I also checked some old screenshots of a dark blue female paired with a peach flesh toned male and one of their children came out with dark brown skin. And if that is the case, then a child could come out with light blue skin as well since the father has lightness to his skin color.

I thought NRAAS’s Genetic Skin Blending is the one blending for me because I turned off Advanced Genetics, and I also did a test by removing the facial blending mod too, and skins from different ramps still blended with Genetic Skin Blending as the only thing active.

Here’s the description I copied for how the facial blending mod works:

How does this mod work?

- Everytime a baby is born in the neighborhood, the mod will randomize the sliders for the newborn
- Click on any sim with two parents and select "Randomize Genetics" to give your sim a new appearence, if you click it there is no going back (except you saved before and load that savegame)
- The offspring needs two parents if this mod should do its work.
- Works with all face sliders (also slider mods)
- The dominance of one parents genes is randomized for each region of the face. Each slider belongs to a specific region.
Regions are like brows, eyes, cheek, nose, mouth, jaw etc. and i plainly adopted these regions from EA.
- The dominance can range from 10% to 90% and is always displayed for the first parent.
- The higher the genetic dominance value is, the more the child will look like its first parent displayed in the notification
- This regional genetic dominance will also be displayed as a notification when a baby is born or when you manually randomize the genetics.
- There is also a noise value calculated for each slider, which is a random number in a certain range, that gets into the calculation for the offsprings slider value. This makes them look even more diverse.
- The noise value will not be displayed
- This noise value can help to prevent genetic decay.
- If the mod is installed correctly you will get a message saying "RandomGenetics started" after loading your savegame.

- RandomGenetics neither change the body sliders for weight, fitness and muscle definition, nor the skin, hair color or eye color.
- Tested with version 1.67.2

Oh wow, that is interesting then. I have no idea why one family would blend despite being different skin ramps, and another would not. They have enough children that I don’t think it’s a sample size issue either.

Could it be the way those skins were created?

The other family is most likely a dominant/recessive pairing when it comes to skin tones/values. It's either or instead of blending. But blending may be possible but it just didn't happen yet. In either case it doesn't bother me.

When I get around to playing TS3 again, I may update my topic of any findings concerning other skin tone ramps and values inheritance.

From what I recall, TS3 doesn’t have any sort of dominant/recessive system. However, there is a pretty high eye/hair color mutation rate to give the illusion of one. That’s why I was stumped at why in your photos, one family blended, and the other did not lol.

As far as skin colour goes, by default the EA system doesn't allow skin colour blending, but with SP it clones a ramp from one of the parents, transfers it onto the child and blends the skin colour. It's totally random, so sometimes you end up with offspring whose skin color is somewhere in the middle or nearing one parent's skin color but it's not exactly the same, just a little bit darker or lighter. Same with Consort's Hair Color Mod and Random Genetics. I play only towns with white populations so there's no genetic skin blending, but hair color and facial blending occurs with those two mods and SP Advanced Genetics on.

Oh, okay makes sense then. I have SP’s Genetic Skin Blending turned on, but their Advanced Genetics module which controls grandparent inheritance, facial mutations, identical twins, etc, turned off since idk if it conflicts with Random Genetics. So far, it’s been working for me now, correctly blending skins from different ramps and producing offspring with unique faces.

Also thanks for the replies everyone!

That's fine, many don't take notice or don't think TS3 has a dominant/recessive system and I have a different opinion from most. I deep delve or as much as I can through observation and being analytical through factual in-game examples. It is odd though that there's not much official information about the genetic system in TS3 because I would have been or still interested in learning how it's coded and how it works from the developers who worked on it. Otherwise, I just go by what I see and experience in-game knowing the basics of genetics and inheritance.

I notice the dominant/recessive system not only in my in-game tests but also through my actual gameplay through my small sample of generations. Originally I thought that, let's say, the recessive/unexpressed genes, such as an grandparents eye color was considered recessive in TS3, and it is to a certain extent until you break the family tree, otherwise the actual recessive genes are the eye colors, hair colors, etc. that are randomly assigned to a Sim that I presume is during Sim creation and hidden somewhere among a bunch of other information about a particular Sim...like the Sim's Data File, Sim Profile or whatever one wants to call it. How else does the game keep track and know of these recessive genes if it is not stored somewhere? Anyway TS3 dominant/recessive system is one of many hidden features and not something the player can see in terms of on the U.I. and cannot be manipulated as it seems to be a part of the locked core of the game's coding. Or so I suspect.

Oh, how so many complain about, "Why does my Sim's child have black hair and no one in the family has black hair?", "How does two blonde-haired parents have a child with red hair?", "No one in the family has blue eyes, why is does their daughter have blue eyes?" I'm confused how some are so confused and don't recognize that these happenings in TS3 are indeed the games implementation of recessive genes. Speaking of my own genetics, who in my family has red hair? Where did I get my reddish-brown hair from? Well, one of my ancestors had red hair. And that's the point in TS3. When we create our founders, they are not considered Gen 1 by the game's logic and therefore is assigned recessive traits. Would have been nice to have the option for both picking the recessive/unexpressed genes ourselves or having it randomly chosen, especially with the RGB/HEX creative freedom.

So for example: The founders of the Rumbaa family, Nathaniel (Brown Hair) and Trinity (Black Hair), one or both of them have two recessive hair colors which can either get passed down to their child or future generations. Out of 15 children, only one child came out with blonde hair (rare) and all the rest of their kids have either brown or black hair. Further testing some of their children have displayed the same exact, hidden recessive gene(s), of their parents. So their children also has the recessive trait(s) of blonde (rare) and/or orange (rarest) hair that gets passed down. Through the generations I have noticed those recessive genes never change regardless of breaking the family tree, as they shouldn't because realistically that is something that is a part of one's DNA that can be passed down to their child who either will become another carrier of said recessive gene or inherits it meaning they show the recessive gene...blonde or orange hair in this case. Of course, when a Sim pairs up with one of the Rumbaa's, then that partner can also have either the same recessive genes meaning a possibly higher chance of a recessive gene showing on the child(ren) or bring new ones into the gene pool altogether.

In the case of Carlston Rumbaa (Brown Hair) and his wife (Brown Hair), their hair color recessive gene pool is: Black, Blonde and Orange. (Only Black has shown up thus far)
And their eye color recessive gene pool is: Green-blue, Grey and Blue (No one inherited these yet but are likely carriers.)
Each pairing has their own gene pool of what is possible to pass down to their child or future generations. I have done enough in-game testing to know that these never change, though for me, rare to see my Sims to inherit. So far none of the Rumbaa generations have anyone with orange hair. But one of the grandchildren came out with blonde hair and the parents of that child has brown and golden brown hair.

I didn't finish that topic over at official Sims forum, but if anyone is interested here's the topic: https://modthesims.info/showthread.php?t=658849
I may copy the rest that I have here over there.

The Sims 3 genetics is one simple XML file, which carries too little information for us to draw any conclusions. It does have skin color blending option, but it didn't work without twallan's SP. I know that there's a default 10% hair/eye color mutation possible which usually means pink eye color and the hideous brownish/yellowish hair color, which are not even blends. Those colours aren't even a possible swatch in CAS. I disabled the mutation as soon as I learned how to do it in order to avoid those hideous mutations. There's also a base 25% grandparent eye/hair color inheritance chance and it's also random, no dominant/recessive genes involved.

There's nothing to debate, but discussions are nice to come to an understanding that everyone thinks differently and is good to see various opinions and/or thought processes behind it. But you know, some just get so offended when others don't think the way they do, see what they see, feel what they feel, live the life they live, as if everyone is based on their individual mentality and life experiences. It's not surprising at all how many are into conformity, but I'm one of the rare few who swims upstream than the majority who goes with the flow and swims downstream.

The story of my life and I love every single moment of it. We all reap what we sow....

Well, I don't think there's any room for philosophical discussions about life or conformity in a thread about...sims genetics. I analysed the XML file which proves that genetics is rather straightforward and there doesn't seem to be any dominant/recessive system and the fact that some sims inherit hair/eye color from one of their grandparents is also present in the XML. It's all just a random pick. I uploaded the family tree of my sims from Moonlight Falls and many sims had dark brown eyes, but for some reason lighter eye colors were chosen 3 times in a row starting with my and Belisama's son (pic. 1). Skin blending, as far as I remember, doesn't work without SP, but I have to check pictures from my earliest games from before I installed twallan's SP or even a separate skin blending mod. I think there was one before twallan's SP, but I'm not sure.

Did you not say, "The Sims 3 genetics is one simple XML file, which carries too little information for us to draw any conclusions."?

And then you say, "I analysed the XML file which proves that genetics is rather straightforward and there doesn't seem to be any dominant/recessive system and the fact that some sims inherit hair/eye color from one of their grandparents is also present in the XML."

So according to you, though contradictory to what you said prior, the XML file has all the coding and programming of the entire genetic system; therefore impossible that there's anything more to it elsewhere despite TS3 not being entirely open source. Thus meaning, not everything can be seen, looked at or manipulated.

Let me ask you this and this can be rhetorical. Why do you think it is common in TS3 that many who share their Sims' generations and genetics here or elsewhere, that there is hair and/or eye colors that the parents' and grandparents' don't have but the grandchildren do have? A mutation? Because my definition of mutation is purple eyes and the yellowish-green brown hair color. Why do you think some of your Sims has lighter eye colors? Is that really a mutation or the game's design and feature (possibly hidden) to imitate the basics of genetics?

Genesis's second wife Avani has fraternal twins. The fraternal twin sister has darker brown eyes while her mother has lighter brown eyes. There's another couple and their daughter has a lighter version of her father's black hair color, a dark grey. So eye and hair colors can lighten or darken based on their parents. It might be rare but it can happen. That's not in the XML file, but clearly it is based on genetics and inheritance by the way it is being used in-game. There is more coding being played out behind-the-scenes.


I already know there is skin blending in TS3 from my own in-game experience both with no game altering mods and just mods in general that have no effect on the genetic system. I don't use any kind of story progression, not even the game's. I don't use anything for hair color blending or anything like that. Anyone can easily create a brand new TS3 folder with no mods or just NRass NoCD if that's what they use to test it out for themselves. Some players are so accustomed to mods and cc that some don't even remember what's in the original game vs the modded game.

You, just like everyone else is free to think what you want. It doesn't affect me whatsoever. Just sharing my thought process as to why I think there is a dominant/recessive system in TS3. You have your own opinion and we can agree to disagree.

Now that I have a rekindled fascination in genetics, I'll use that basic knowledge and inspiration for some new character designs for the children of my original characters.