prebaiting for carp can work but you got to pick an area that nobodys else fishes makes no diff if you prebait with strawberry boilies and then i come along and fish exact spot with pineapple i will catch the fish you prebaited for. So the lesson i learned was pre bait where no other angler casts to, does the colour of a boilie matter ? well since we dont see things as carp do who knows ive caught on crap brown ones and on fluro yellow i think flavour is more important as carp hunt by smell in the main on a lake i fished 2 yrs ago the guys were pouring in a certain expensive boilie so me bieng me bought a mega cheap high leakage brand and caught bagfulls.On the subject of making them using a pretty standard recipie and adding a little tweak works well hope this helps