First impressions of Elixir's core

Can you please try with this comprehension:

  for\
      <<red::8, green::8, blue::8 <- b>>,
      into: "",
      do: <<div(blue, 2),::8, div(green, 2),::8, div(red, 2),::8>>

We treat those as filters and I assume yours do not, which may cause differences. Just for a more apples to apples comparison. Thanks!