Windows > Color Picker > Macintosh Color Picker

The top of the Macintosh Color Picker window lists several different ways in which you can pick a color, such as Color Wheel, Color Sliders, Color Palettes, Image Palettes, and Crayons.

If you use the Color Wheel, click anywhere in the color wheel to set the hue and saturation. Minimum saturation corresponds to the center of the wheel and maximum saturation to the edge of the wheel. Move the slider on the right to set the brightness.