My favorite color for toys is pink, but I prefer to have each of my toys to be a different color. It's easy to tell a partner to "grab the purple one" and get the toy I'm thinking of than to tell him "grab the Lelo Mona" He will never learn the names of the different toys so having ways to distinguish them is good.
Bluuuuuuuuuue!!! Though I actually like having a variety. I think I like blue, white, and pink the best, and I also really like black and purple. But generally I'll go for whatever color a toy looks best in, and the precise shade does make a difference.