To start with read this very recent thread ...
http://www.monsterfishkeepers.com/forums/showthread.php?t=371669 ... where there is a huge amount of great info and discussion.
Basic principles for flowerhorns are that they are basically amphilophus-type omnivorous foraging cichlids in their body type and dietary needs. So they need some veg matter in their diet. THey obviously alos need reasonable amounts of protein and essential vitamins in the diet, but not too much fat.
Whether you choose to supply them with this with one or more pellet type or by a mixture of foods, of your own concoction is your own decision.
Personally, I am tending to feed high quality pellets as a staple diet (NLS, Hikari, Ocean Nutrition etc), with occasional treats of bloodworm or prawn. I would also feed shelled peas, but all my fish reject them.
I am highly skeptical of these so-called flowerhorn super-foods that claim all sorts of amazing effects on kok growth and colour. A flowerhorn is essentially no different to any other colourful cichlid. All they need is a decent, balanced diet with all the basic nutrients and appropriate trace minerals and vitamins etc. if they get these, then the rest is down to genetics mainly (although colour and kok growth is also highly affected by the environment that the FH lives in).
I have one really kokky FH, and one really, really pearly FH. They both eat the same food and live in almost identical environments. The excellence in their own particular feature is down to genetics not food.