Really there's no secret to good growth and color. As others have said, "good" water chemistry, lighting, and flow as well as stable conditions for all of the above. Now, what "good" means varies from coral to coral. Sometimes the trick is to simply do routine water changes and don't mess with anything else. Take pictures of your coral every month or so, that way you can monitor growth. Like watching paint dry or water boil, it'll never happen if you're watching it. What fast growth means also varies greatly from one coral to the next. Even 2 different colors of zoa may grow 10 times faster than the other with identical conditions.
IMO, water chemistry most affects coral growth. Lighting most affects color. Flow most affects growth patterns. Of course it's not that cut and dry, but those seem to be the biggest factors IME. Each parameter affects color and growth. Just get them in a good range and stop tinkering. I don't know of any coral that likes changing parameters. It's almost like every time you tweek lighting, chemistry, or flow all growth stops until they re-acclimate.
