Can a baby have a combination of traits transferred by the parents? like: B=black color. b=white color. e.g.: one parent has genotype for skin color as (BB) and the other parent has genotype for the same trait as (bb). can the child have the skin color which not too dark and not too white like brown?

Yes (I'm tempted to say "of course", as I would be surprised if you had not personally met families where the children had phenotypes intermediate between their parents' phenotypes ...)

This phenomenon is called **incomplete dominance**. Now that you know the correct terminology you can easily do a web search and get lots more information ...