Unfortunately, I don't have much of a clue of what's happening here. I had decided to erase my save file to test the game from beggining to end and noticed the colors weren't changing in the initial screen.
I did notice that some of the pixels around the eyes of the penguin change normally (probably because its a separate animated files, unlike its body), but the penguin remained red. After further testing it seems this only happens if you edit or replace any file exclusively inside the "UI" folder from Game.rdt


However, the playercard functions normally if you buy a color from the clothing catalog. It seems to be an issue that only happens to the initial "Choose your penguin" screen from when the game creates a new save file.