While dragon pups are commonly bright and colourful, the tones of adult dragon scales tend to mellow out into earthier variants, shifting to browns and greys and muddy greens. They’re the opposite of many animals, who tend to favour drab, elusive offspring and gaudier adults.
Muted tones on adults makes sense; they’re hunters, and bold colours would do them no favours. But why the babies are so vivid is still up for debate. Some have reasoned that, as many dragons enjoy collecting gems or precious metals, that their eyes are attracted to bright things, and bright babies would be easy to notice, admire, and adore.