1. RBG (Red Blue Green)
2. HEX (Hexadecimal)
3. RGBA (Red Blue Green Alpha)
4. HSL (Hue Saturation Lightness)
5. HSLA (Hue Saturation Lightness Alpha)
Click on any little colored boxes at the end of the text-boxes, a color Picker will pop-up. Now Select the color that you want. You would see that all other
boxes change to that color and the value for the color is filled in all text-fileds. The Background Color of the page also changes to give you a feel as in how the color looks.