I support this idea, especially since DA CHANGED THE SIGNATURES! With the original background color and new signature color and small font text I can barely see signatures anymore. I'd like, perhaps, a darker background option. And if this goes through, please, not just something else exclusively for premium members. I can't afford a premium membership and it's just not cool to exclude EVERY little thing from those who are unable to pay anything.
The current colour is nicely soothing, not too flashy and it's what everybody associates with dA so personally I wouldn't like them changing it at all.
The color of the site is something like a logo. It's what dA thinks people will identify it with. Maybe dA could have an option where you could change the color of dA but have the default dA the color it is now. I'm not sure how hard that would be to build into the site though.