when carrot, choclate chip cookie, plain dont, walnut,and oil rubbed on a brwon napkin ,the color changes?

Question

when we rubbed the four fat items on the brown napking and poured a drop of oil on it , the spots on the napking where the food was rubbed changed its colour. why is that so ?/

Answer 1

Because fat tends to absorb easily, thats why it is bad for us to eat a lot of fat because it will easily absorb in our body and it is hard to burn off.

Answer 2

because when things are wet its color is darker

Answer 3

lol