should i ask my bf?

ok he’s not my bf i’ve only been talking to him for a week but he’s super sweet, etc. i’m getting my nails done tomorrow and idk if i should do his favorite color just to have a subtle show that i like him or if i should ask him what color he thinks i should get. last color i got my nails were blue and that was two months ago and i don’t really want to get blue again but also that is his fav color... should i ask him or just get his favorite color?