Kenyi cichlids lost color after 2 days from store.?

Cichlids can change their color when they are stressed, but your chemistry looks good. How old are your bulbs? 5-8 months(running 8hrs a day) the bulbs have lost 50% of their spectrum. The fish don't rely on the light for their survival, but the pigments in their skin can react to the light. The number of fish, and the size of the tank might stress out the fish???Inch per gallon at full grown lenght.