require "bitmap"

local bmp = bitmap.of(400, 400, color.white, "Draw a sphere")
for n = 1, 100 do
    local clr = bitmap.rgbColor(2 * n, 2 * n, 2 * n)
    bmp:circle(math.round(150-2 * n / 3) + 50, math.round(150 - n / 2) + 50, 150 - n, clr)
end
bmp:view()