One Finger is not enough
Use Left Mouse Click to apply a color to fills, solids, and other color properties.Use Right Mouse Click to apply to strokes.
This also works when removing colors.
Click a color to apply
Simply select any shape, text, solid, or other color property, and click a color from the palette to apply.
Sample the active comp
Simply click the sample button and a beautiful palette will be created based on the active comp. Colors samples pixels from all around the image, and sums them down to a compact, easy-to-use palette.
Make a gradient
Shift + click a color to enter gradient mode. Move your mouse around to quickly preview different combinations. Satisfied? Select the remaining color to create a Gradient Ramp
Send Back to Comp
Colors let you send the active palette back to the comp in many interesting ways.
Press the arrow that is facing the Comp Icon. From the list, you can select one of many optoins.
Pressing "Send to Comp" will create shape layers in a pre-comp which look exactly like your palette in the script.
This comes handy if you want to visualize the palette you used in the current frame, or actually use this palette as shapes, and animate them.
You can also use this as reference for you, or if you want to save the palette in the comp so you can load it back to Colors later on.