In some animations, some models could temporarily clip through others, causing a visual effect that makes things look unnatural. In these cases, it is better to make the colors and textures of the overlapping parts as similar as possible, so the clipping effect can be reduced. Check the following example:
On the left, you can see how in the hip area, the black pants clip in and out through the hoodie making it look odd and unnatural. On the Right, you can see how this effect is reduced by matching the textures of the thighs and hip models.