This is one of those Levels where the right color blocks are essential.
If you do not get enough of the correct color for the butterfly early in the game, just quit and try again.
Try to join the correct colored blocks together with the paint booster.
Make use of X2 blocks to increase the number of blocks counted in a group.
If you can, get 16 blocks together in one big group to release the butterfly in one move.
Otherwise make the matches of that one color close in time, as waiting too long between filling the butterfly seems to make it need even more than 16 blocks!