What is the most important factor to the color?

[severum]

Generally WCs show better body color than F1. Why?

Is it the water quality including hardness, PH, NO3 or food?

What should I do for my tros to show best body color? (I have RR and Duboisi) 

My F1s and F2s of WC RR can show same color as their parents and grand parents?

Which is more dominent factor? Water quality or Food?

In water quality, which is most important? Hardness? PH? NO3? or else?

Sorry for lots of question, but please share your experience and thoughts.

[Mastiffman/ Duramax7Man7]

Not from my experience. I think that F1 are more intensely colored on acct of better more diverse diet of color enhancing foods for a longer duration of their lives than WC. And if bred correctly, you can really focus on selected traits. (i.e. only allowing the best males to spawn with the best looking females and matching their traits).

I think that often times people just flat out don't take the best care of the fish and that over exposure to nitrates will make them turn darker. Fade their colors. Fish color is produced in their Chromatophores. IIRC, The black portion is contracted allowing the bright colors to display. When the fish is over exposed to nitrates or are in lower Gh (magnesium sulfate) environments and lacking proper nutrition, the black chroma expands, consuming the space in the skin cells that gives a darker appearance.

[mikevxr]

my first group of Ikola were bought locally and yellow banding looked dull - however once settled and ph of tank water adjusted from original 6.5 to 8 their colour improved, still wasn't great but after selectively breeding best females to best male for past three years their colours are far far better with prominent yellow banding. That said however if they are stressed or unhappy the colours darken down especially first thing in the morning when lights initially come on slowly. - just my observations.