outerColor = -7898370
innerColor = -12633735

innerWidth=320
innerHeight=200
borderHeight=40
borderWidth=32

width=innerWidth+borderWidth*2
height=innerHeight+borderHeight*2
pixels={}

for y=0,height-1 do
  for x=0,width-1 do
    local isInner = x >= borderWidth and x < width-borderWidth
      and y >= borderHeight and y < height-borderHeight
    pixels[x+y*width+1] = isInner and innerColor or outerColor
  end
end