The first step to mastering the color wheel is to understand undertones. There are two types: cool and warm. The colors grouped with these undertones are exactly what you would associate with their names. For example, red and orange are reminiscent of heat, so they are “warm,” while blues and greens remind you of the sea, therefore “cool.” Colors like yellow and purple fall on the cusp of the two undertones and can actually go either way. You can have a red-purple or orange-yellow that’s “warm,” or a blue-purple or green-yellow that’s “cool.”
The second step of knowing the color wheel is understanding what colors complement each other. To do this, simply pick any color on the wheel and find the one directly opposite. For example: red and green, blue and orange, purple and yellow. Easy-peasy.