http://gambaswiki.org/bugtracker/edit?object=BUG.1035&from=L21haW4- Comment #1 by Jussi LAHTINEN: Binary presentation of number 16777215 is 111111111111111111111111 (so, 16777216 is 1000000000000000000000000). So I guess 24 bits is the maximum value. I have no clue where the limit comes.