I did a little experiment of my own, and I've come up with a theory on how the rainboos work.
Purple Male.
Green Female.
Baby #1 came out with a blue-green tone, almost alien-like.
Baby #2 is much more blue then Baby #1, but still has a bit of green.
Baby #3 seems to have her mother's skin tone entirely.
Baby #4, the only purple baby, is the opposite. She got her tone from her dad, though I think it's a little more blue than her father's.
And Baby #5 is blue.
So, here's my theory. To put it at its simplest, if a light-skinned Sim had a child with a dark-skinned Sim, that child would be either light-skinned, dark-skinned, or somewhere in between the two. A similar thing occurs when the colors are more different. (Ricalynn's Grims being either red, normal, or a lighter red)
The same thing happens with the rainbow slider. In the above example, Purple Male and Green Female could have either green babies, purple babies, or somewhere in between the slider. The difference is, of course, that there are intermidiate colors. The rainbow slider isn't just one color. Therefore, Purple and Green could have purple babies, green babies, or a skin tone
in between purple and green. (In this case, blue and turquoise)
How much difference in skin tone the nooboos could have depends on the distance between the two colors. If a purple and a purple breed, the child pretty much guarenteed to be purple. But, if one is purple and the other is orange, there's a lot more colors that could show up. (purple, blue, turquoise, green, yellow, and orange) However, the nooboo could
not be red or pink, since those colors are not between purple and orange.
So, to summarize, the larger the distance between the two skin tones on the rainbow slider, the more colors the nooboos could be.
