To understand a color wheel, start with the primary colors (red, yellow, blue), and see how they form secondary colors (orange, green, purple) by mixing them in equal parts. Tertiary colors are made by mixing a primary and a secondary color, and are found between them on the wheel. You can then see color relationships like complementary colors (opposite each other) which create contrast, and analogous colors (next to each other) which create harmony. Finally, understand that the wheel is split into warm colors (reds, yellows, oranges) and cool colors (blues, greens, purples).