Simulate Amiga Copper effects?

My best effort (ie. hacked together over the last 5 minutes) -- play with colour algorithms...

Graphics 320, 240;, 0, 2

Repeat

	Cls

	For y = 0 To 239
		Color y, y / 3, y / 4
		Line 0, y, 319, y
	Next

	Color 255, 255, 255
	Text MouseX (), MouseY (), "'Copper' feel of this..."
	
	VWait
	Flip False
	
Until KeyHit (1)

End