Considering the idea that gene scrolls may be a physical item/incantation in FR lore, I think that genes(mostly applied, though I could see an argument for naturally obtained ones) could definitely have some bearing on personality! Here's a few headcanons of mine:
edit: fixed some formatting & grammar errors.
- Metallic/Alloy could reflect a dragon's value of strength, or perhaps vanity/pride(see also: Iri/Shim); they're most commonly applied by members of Earth or Lightning, as well as mostly land-dwelling breeds such as Ridgebacks and Snappers.
- Savannah/Safari are either natural or painted/conjured markings, not unlike warriors' paint; they're most commonly applied by members of Plague, Nature, or Shadow, especially those who value secrecy or being more in touch with the environment around them.
- Giraffe/Hex - This pair could honestly go two ways - they could either be natural markings similar to cracked skin found mostly in drier, flatter areas such as certain regions of Earth or Ice, or act as a more 'modern' design adopted by fashion-seeking dragons of any flight.
- Iridescent/Shimmer are usually applied by wealthier dragons of Light or Ice(maybe Water as well?), who usually are prideful of both themselves and their element and wish to represent it the best they can.
edit: fixed some formatting & grammar errors.