They are just great, your colors ! Looks a bit like the hand would be behind a dirty window ? Its such a good effect you've created. Maybe the red could be a little tiny bit more muted down into an earthy tone, but that's just taste, isn't it ?

Colors can only be judged based on the colors around them, in relation to each other. This example doesn't give me enough info to tell you what is or isn't working. What you are doing right is thinking about warm and cool colors, which is good. Know that color has three other attributes: hue, chroma, and the most importantly, value.