I think it's quite possible for Finwë to have a recessive blond gene in there, but in the case of Fingolfin and Finarfin, Indis's dominant blond gene probably took over. Fingolfin's hair color isn't really mentioned, so he can be either dark or blond. I'm much more inclined to think of him as dark, since I have a penchant for tall, dark Noldor.
The way that the genes for red hair work something like this. Those genes, actually, are incomplete dominant, which means that they will blend colors with other incomplete dominants or dominant. Fëanor probably had a black dominant gene, and a silver recessive gene (I remember reading somewhere that Miriel had silver hair, correct me if I'm wrong.). Nerdanel had auburn hair, which means that she had a incomplete dominant red gene and a recessive brown gene. So 50% of their children should have red hair, 25% black, and the other 25% should have brown (or something like that).
The website that I got this information from is
http://www.luchau.org/writing/elven_genetics.htm
Try checking it out, it has a lot of helpful information on Elven hair colors in general.
The mechanics of red hair genes work something like this. If one parent has a dominant dark-hair gene, and the other one has a