^ I think I agree with this. If it's true that the fish lose color intensity as they grow, my guess is they've been heavily color-fed or hormoned like so many discus are. A lot of hormones do pretty nasty damage to fish internally and most don't live very long. If they're color-fed, you'll have to continue doing so in order to maintain the intensity of the red. Most people don't have access to the types of color feed additives that are used in fish like this.