I think pink is less clearly a shade of red (it can go a bit into blue), while "голубой" is simply light or pale blue: AFAICT it's used as an alias, and one may

I think pink is less clearly a shade of red (it can go a bit into blue), while "голубой" is simply light or pale blue: AFAICT it's used as an alias, and one may call it "light blue" as well.