I've been doing a lot of work with yellow diamonds recently and had this thought. Most yellow diamonds are not actually a super vivid yellow colour - most are a variety of shades of pale yellow with differing tints of brown. And when you also get into the least desirable colour on the diamond grading scale, its almost in the same colour family as yellow diamonds.
The idea is to create a jewelry collection / product line branded 'Natural Blonds". Because the diamonds are "blond" in colour, and they are natural (not lab grown). You could even re-name the different colours based on the different shades of blond. Instead of it being a "fancy light yellow", its platinum blond. I'd be willing to bet you'd notice you wouldn't need to discount certain colour shades if you gave them desirable hair-colour names.
The aesthetic sells itself. Use exclusively blond models with an effortlessly superior vibe compared to those lab grown bottle blonds. It's giving old money, it's giving clean girl. It's very gen-Z while also very timeless. I think it would sell well.