Colorselector: Fix out of bound read.
Colorselector: Fix out of bound read.

high should be the last item of the array, not the length of the array.
As part of this change, I also changed the code to use the better way of
getting the array size.

CID1339827

tasn/elementary,tasn/elementary,tasn/elementary,tasn/elementary,rvandegrift/elementary,tasn/elementary,rvandegrift/elementary,rvandegrift/elementary,rvandegrift/elementary