There are 4 sliders each for text and background. The sliders control the 4 components of a color setting: transparency, red, green and blue.
The buttons show the hexadecimal value for that component. A hexadecimal value may be typed into the button by touching it. The 4 hexadecimal values may be combined into a color value to be used in an Android app.
I may provide some more options, if requested by email.