I.. don't know? In the end, it would probably have been some kind of flavor trait that you look at once and then forget about. Colorblindness is something that has some influence on using the game's interface in many different ways, but I cannot think of any meaningful application within the context of gameplay itself (except maybe for painters). I don't think sims "see" color. Not even their favorite color has any gameplay implications. It's just a talking point.
And the shader itself would probably not be very useful for myself. If, by chance, they pick the same flavor of color "blindness" I have, I wouldn't notice a difference with or without that shader. If they pick any of the other flavors, it just looks weird. Most people would probably switch it off quickly.
Which means I can see why that feature was axed. Then again, they have stuff like "Never Nude", which means it wouldn't be too far out of place.
