White, black and gray colors are neutral colors.
So, if you are a cool color person, cool colors complement you well. If you are a warm color person, warm colors complement you well. However, if you are a cool color person but matched with warm colors, you don't stand out with those colors. Same goes with warm color person with cool colors. Unless you are neutral person, which means any colors will complement you well.
How do we know which color group we belong to? Here is a link to know which group you are. http://www.womenshealthcaretopics.com/bn_makeup_Are_You_Warm_Cool_or_Neutral.htm
Or you can base on your senses to judge whether pink or orange color suits your skin tone. If pink suits you more, then you belong to cool color group. If orange color suits you more, you belong to warm color group.
When you match clothes, do not match both clothes with warm. Must be one warm and the other cool to complement each other or you can choose to match with neutral colors. If both are warm colors, then you are too warm in color, which is abit over-doing it.
All this while, I've thought myself as cool color group, which is wrong!!! I'm more suitable of warm colors. No wonder I wear silver accessories, it wasn't flattering at all. Now all my wardrobes have a number of cool colors clothes, which doesn't complement with me lah... No wonder my attire wasn't flattering at all lah...