anchor: love.graphics.setBackgroundColor
  Sets the background color.
  love.graphics.setBackgroundColor( red, green, blue, alpha )
  red number The red component (0-1).
  green number The green component (0-1).
  blue number The blue component (0-1).
  alpha (1) number The alpha component (0-1).
  love.graphics.setBackgroundColor( rgba )
  rgba table A numerical indexed table with the red, green, blue and alpha values as numbers. The alpha is optional and defaults to 1 if it is left out.