@Inna22 I don't have a favorite color for towels, but I have never done white. Honestly, I haven't had a real problem with stains on towels. I do use separate washcloths, but haven't really had a problem with stains on those either. However, they are cheap enough that they are easily replaced if I do.
One thing I do do is have separate color towels for guests, because I only have one bathroom, and I want guests to be able to keep track of whose towel is whose- pretty challenging if they are all the same color.
I also haven't had a problem with darker colored towels bleeding. I've been buying decent quality all-cotton towels at either Amazon or Macy's/similar department stores. I use vinegar as a fabric softener and I do think it helps them last longer, as there are no strong chemicals at work.
While this isn't a direct answer to your question, I hope it helps. Kia