Following on from Tomasz's answer, you can also programmatically set the shade of the entire button using the PorterDuff multiply mode. This will change the button colour rather than just the tint.
If you start with a standard grey shaded button:
button.getBackground().setColorFilter(0xFFFF0000, PorterDuff.Mode.MULTIPLY);
will give you a red shaded button,
button.getBackground().setColorFilter(0xFF00FF00, PorterDuff.Mode.MULTIPLY);
will give you a green shaded button etc., where the first value is the colour in hex format.
It works by multiplying the current button colour value by your colour value. I'm sure there's also a lot more you can do with these modes.