The basic principle of color is that red, yellow and blue are the three primaries that can’t be mixed from anything else. The secondary colors are made up of two primaries each: red + yellow = orange, yellow+ blue = green, blue + red = purple. Red, orange and yellow are considered the warm colors (think fire), while blue, purple and green are cool. A classic color combination is predominantly warm (or cool) with a touch of the opposite. Like this one.
