Ooh, I like Myron's and Richard's suggestions, too!
If you go with less contrast, add the color to the white not the other way around. Do a test sample. Depending on the
paint, dark colors can darken white fast, while it can take gallons of white to lighten a dark color. If you have the
paint pre-mixed at the store, they can usually provide a lighter color-matched tone using the same base as the white for a perfect color combo.
Be careful of the base colors. I don't know if all paints work this way, but I once saw a family room with red carpet and off-white walls. It was horrible and the owners didn't like it. Turns out the off-white was made that way with the addition of yellows. So although the wall wasn't truly yellow, by pairing that
paint with red carpet the combination was awful.