You can change the style to RGB,HSL, or Hex Change styles by clicking the small arrows in Right-Bottom Corner The arrows are located in the box that says "RGB"
To use RGB for the color picker Select 0 (off) and 255 for (full brightness).
Combinations of numbers will change the color.
HSL is broken into three branches-Hue, Saturation, and Lightness.
Hue (H): Position on the color wheel from 0 to 360 degrees.
Saturation (S): Purity or intensity of the color.
Lightness (L): How bright the color is.
Hex works almost the exact same as RGB except it uses a code
Hex is written as #RRGGBB where each pair of characters controls a color channel.
an eyedropper tool is located in the first row. It will show the id of either RGB,HSL,or Hex depending on which you choose.
The rest is really self-explanatory (sorry for different font)