Bralettes are a wonderful option! So many current fashions feature open backs and interesting details on the back of the dress or top, but it makes it difficult to wear a "normal" bra.
Bralettes are an amazing option because they give you the support and coverage of a regular bra, but they are delicate and pretty enough that it makes it okay for them to show.
I think it is best to go with neutrals with bralettes so that you don't have to buy the whole rainbow (but you should if you want to!). That's why I mostly feature shades of cream, nude, off white, black, etc.