There are three properties of color: hue, value, and saturation. The hue of a color is the name - pink, blue, red, green, etc. The value of a color is how light or dark it is - what tint or shade it is. Colors here would include baby blue, pink, maroon, lavender, etc. The saturation is the relative brightness or dullness of a color.
A bright purple has a higher saturation than the dullest purple you can think of. A color wheel shows only hues and a few values. Saturation is best seen on the color palette that comes up in many drawing applications on the computer. The closer to the middle of the screen the color, the brighter the color is.
