GREAT COLOR, like great interior design, has great depth. Light, dark or somewhere in between - it really does not matter when the color has depth.
When choosing colors I am always guided by which colors display a richness - a feeling of warmth and surrounding. The best analogy I can give is this. Take a can of white paint and add any color to it. A plethora of choices will emerge as you add more and more color. The end result, while yielding something pleasing, will always elude that depth that I am looking for.
On the other hand, take a can of rich deep color, let's say a vibrant blue or red. Add white or ivory to that color until it reaches the desired tone that you are looking for. Whatever amount you add or how light you take the tone, the color will retain it's depth because it is inherent - the source, if you will.
Paint is tricky. It takes study and comparison - but understanding what to look for is
a great beginning to achieving beautiful, long lasting results. My advice to my clients who want to do it themselves is this:-
Do your homework. Compare many "colors" of what looks in the beginning to be the same color. The comparison will reveal many things that are not visible with a single choice. Once you have studied the colors and chosen the one that you can now see is what you truly are after, then paint and don't panic. The color on the wall will never be exactly what you imagined but I have found that it is most often as good or better than I planned. The trick is to widen your expectations and to feel confident that your pre-work has been done.