Color Picker allows you to select a color from the color spectrum (called a color slider) or define your color numerically.
To select a color visually, do the following:
Drag the color slider to get in the range of the color you want.
In the Color Field section, select the shade of the color by clicking and dragging on the circle.The dialog box displays your new chosen color.
Note: In the Color Values section, the numeric values also change accordingly to represent the exact shade you’ve chosen.(Optionally) If you know the numeric values of the color you want to use, you can enter the values in the Color Values textboxes.
For example, RGB values are based on brightness levels, from 0 to 255, with 0 being black and 255 being the pure color or white.