Is there any significant difference in buffer springs that have different colors?

I have some that are shiny almost chrome or nickle looking (maybe chrome silicon)?  I have some that have an almost annealed/bronze like color. Others have a dark like oxide or park'd look.

What the heck is the deal?  Oh and then there is the whole flat wire thing but I really just want to address what the color differences could mean.

Do these colors indicate, metal composition, type of metal etc?