# note: Color-indexing transform with 2 colors, so 8 pixels are packed per
#   byte.
# expect: ok
# exercises: num_colors <= 2 gives bits = 3, the densest packing, and
#   shrinks xsize to ceil(w / 8).
lossless
width 8
transforms color_indexing
palette_colors 0xff0000ff 0xff00ff00
code green 0xaa