I've always seen myself as a colourist and am instantly drawn to gorgeous dramatic colours!
When I first started painting 40 years or so ago I always chose as many colours as I could see in the landscape or item I was painting, in an attempt to get as close a representation as possible. However I was often disappointed with the result.
I've since learned that when it comes to colour less is more and that there is a particular power in using a restricted palette.
This sculpted paper painting has just 3 colours but still creates drama and impact (not a great photo but you get the idea).
A really good exercise is to try and paint a picture using a very limited palette say just two colours - burnt sienna and ultramarine are good choices - and see how many tones and colours you can achieve. The painting should have a lovely cohesive feel when finished.