Geez, sorry for the palette-mess... not used to restrictions =) Trying to refine. Didn't know transp. counted as a colour =)
As has been pointed out, there are errors in this piece. Currently your colour counts are:
Top left - 5
Top right - 7
Bottom left - 7
Bottom right - 12
Fix and resubmit!
I love it, please fix!
There are more problems but none fatal; see edit here.
As TRH said, transparency counts as a color so you have one too many in each quarter. It's easy to find an unnecessary color to remove in each except in the lower left where it's a bit more tricky.
Also, the middle horizontal line crosses the face 2 pixels below the brow hairline, so that the 2 upper quarteres actually include even more colors. Lowering either hairline or lady fixes it.
Then, your darkest color actually is 2 undistinguishable colors (one is mapped in red in edit). Easy fix.
If this is supposed to be a challenge entry, please correct to follw the rules before Sunday night or it will be removed from the judging (but left in your gallery.)
Very nice, I likes.
Top left has 3 colors. (and top right 4, bottom left 6, ect.)
Blakc, if you didn't know, transparency counts as a color! D:
For future reference. No need to delete and re-submit as new.
Just hit the 'edit details' link up there and upload revisions :)