h=ceil(graphheight/4)
for row=1 to 4
  w=ceil(graphwidth/(8*row))
  c=255/(8*row-1)
  for n = 0 to (8*row-1)
     color 255-c*n,255-c*n,255-c*n
     if row/2 = int(row/2) then color c*n,c*n,c*n
     rect n*w,h*(row-1),w,h
  next n
next row