Answer
Create an xml file in the res/values directory called as colors.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<color name="White">#FFF</color>
<color name="Black">#000</color>
<color name="Grey">#7F7F7F</color>
<color name="DarkGrey">#4F4F4F</color>
<color name="Green">#0F0</color>
<color name="TransparentGrey">#7F000000</color>
</resources>
You can define what ever colors you want as resources as it is shown above. Once defined, the Android compiler will automatically create resources identifiers in the R file that you can refer in your code as show below:
public static final class color {
public static final int Black=0x7f060001;
public static final int DarkGrey=0x7f060003;
public static final int Green=0x7f060004;
public static final int Grey=0x7f060002;
public static final int TransparentGrey=0x7f060005;
public static final int White=0x7f060000;
}