At first I really didn't like it, but it grew on me everytime I played it again. Good job!
A few kinks to work out (some of them are in other comments, but I'll reinstate them):
- You can't restart a level until you lose.
- Can't deselect squares.
- Some sequences are impossible (I particularly remember a Red-Yellow-Yellow-Yellow-Yellow sequence, but there were still blue squares!!).
-Sometimes I didn't have the correct sequence and the game said I won (admittedly this didn't happen very often, but it was worth mentioning).