Android changing a color's brightness

Question

I want to change the brightness of any given color (Note: I am not talking about screen brightness), I have looked at the Color class, it has a few methods for conversions between RGB and HSV, I'm a newbie in this area. To start with, how do I change the brightness of red, if its value is spefied in RGB (#FF0000)?

Answer 1

The easiest way would be to convert the color to HSL (not HSV! they are different - see http://en.wikipedia.org/wiki/HSL_and_HSV) and change the L component - increase to make it brighter, decrease to make it darker.

Answer 2

Considering that you are talking about brightness (color enhance) and not luminance (white amount), your model is the HSV (aka HSB) and not HSL.

On fast briefing, if you enhance the V channel on HSV over, lets say... some blue, you have a "more blue" color. If you enhance the L channel on HSL model you have a more "clear and washed" blue.

The android.graphics.Color class have built-in support to HSV model. Use Color.colorToHSV() and Color.HSVToColor() to edit the brightness value (or hue, or saturation, if you like).

On HSV model, H (hue) define the base color, S (saturation) control the amount of gray and V controls the brightness. So, if you enhance V and decrease S at same time, you gets more luminance, in pratice.