Use the two colour bombs (not together) on the bottom to help clear the board and provide a better chance of making more colour bombs.
The level is not too difficult, but the chocolate can easily dominate the board.
If playing on iOS, try to get a board where you can immediately release a colour bomb and if possible, destroy the colour of candy above the other one to release that one too. Other wise, the chocolate will block the colour bomb and make you waste more moves to clear it.
Don't rely on the mystery candies for help. Half the time they will contain blockers - maybe even very harmful ones like candy bombs. You will rarely, if ever, obtain a colour bomb from them.