Sets the background color
VGA.setBackgroundColor(color)
RED = 0xE0
GREEN = 0x1C
BLUE = 0x03
YELLOW = (RED|GREEN)
PURPLE = (RED|BLUE)
CYAN = (GREEN|BLUE)
BLACK = 0x00;
none
VGA.setBackgroundColor(0xE0); //set background color to red
VGA.setBackgroundColor(0x1c); //set background color to green
VGA.setBackgroundColor(0x03); //set background color to blue