Phil Robinson, Founder of Paint The Town Green suggests painting 2 coats of sample colours onto the middle of a piece of paper. When the paper is dry cut it out so that you are left with a solid block of colour. Move the paper around the room and consider it at different times of day.
Colour is all relative, so put colour block samples together to see which colours harmonise and suit the setting.
Phil's top tip for choosing colours from samples:
"It's all about the light and getting the right colour for the space "
Here's a link if you are thinking of ordering some sample pots to help your decisions :