It is very easy to give color opacity effect in android. Best way to add transparency by percentage is by using alpha channel in android i,e 8 digit ARGB values, Alpha-Red-Green-Blue hexadecimal. Which is appending a 2 letter value to hexa code of a color. If you know alpha codes for transparency then you don’t have to create separate graphics for achieving such transparency effect. It is time saving and maintainable.
Transparency is controlled by the alpha channel (AA). Maximal value (255 dec, FF hex) means fully opaque. Minimum value (0 dec, 00 hex) means fully transparent. Values in between are semi-transparent, i.e. the color is mixed with the background color.
To get a fully transparent color set the alpha to zero. RR, GG and BB are irrelevant in this case because no color will be visible. This means #00FFFFFF (“transparent White”) is the same color as #00F0F8FF (“transparent AliceBlue”). To keep it simple one chooses black (#00000000) or white (#00FFFFFF) if the color does not matter.