I usually use
Adobe Kuler (Adobe Color CC) if I can't decide on a color scheme from the start. The site is pretty user friendly, and you can search by numerous topics. Most of the color palettes are made up by other users. You also have the option to store your color palettes under your username (My Themes) so you can access them from anywhere. It's a pretty useful tool. I'll sometimes also Google or Pinterest search related topics and see what color scheme has been used particularly for time period stuff.