Is there a StackExchange site appropriate to ask a question about web design?
I'm needing some suggestions about which colors to use for a very dark themed website, where should I ask this?
Read both sites' FAQs carefully and search for similar questions before you ask your own.
At the moment, the question is too broad for most every site dealing with this subject. If you could narrow down your question a bit...
General opinion-poll type questions are off topic for most any question on Stack Exchange. For some background on that, check out Good Subjective, Bad Subjective.