blink_screen Flash the Screen

• blink_screen

• blink_screen <r> <g> <b>

• blink_screen <r> <g> <b> <d>

• With no arguments flashes a black full screen window for 50ms

• With three arguments, integers in 0..255 flashes a window of that colour

• With four arguments, integers in 0..255 flashes a window of that colour for d ms