If you want to paint a bold, bright color in a room, a way to do that is by painting one wall in the room the bold color, and the other three a tint (lighter version) of that color. This will soften the effect and tie the entire room into the scheme.
You can also do a schemes of tints and shades using a tint on the ceiling, and shades as trim colors.
If you use a company such a Benjamin Moore for paint, they provide easy to use color samples that show the color plus its tints/shades. Check out the Virtual Fan Deck from Benjamin Moore to see what I mean.