I look for color inspiration all around me. I am primarily drawn to earth-tone colors, so those are the colors I use the most. Artwork, people's outfits, nature etc all around me is full of different colors. Just the other day I had thrown a silver-grey vest over a russet top and now I want to investigate that combination.
If you are really stuck, look for patterned items that draw your eye and duplicate their color scheme. Either fabric (which you use as focus fabric or not) or ceramics, other objects with a range of colors that you can copy.