This will cause the colourbomb to hit the yellows usually and either unlock, change or collect them, whichever is needed.
I wasn't as lucky as you guys were on 4550 I started with a full bolt and had a double cb plus a fish and I used 11 hands 14 hammers and a 2 saucers and I couldn't get that last square cleared in the middle plus I used up what little gold I had.
I heard on the Wednesday Club that it doesn't work for everyone.
I will try some of these things.
Prepare yourself for a big boom and a Candy avalanche! Might talk to support about the disappearing bot.