Trialpears has just submitted some DLC Game Info for
Halloween 5 Pack for Coloring Pixels:
Trialpears said:The EGX achievement should be moved into an independant title update since it's available for free. The most logical name would Bonus Image 4 Pack, but that was taken by the subsequent Bonus Image so deal with that as you like.
Also the not yet released Community 6 Pack is currently known as Unknown Pack