No, I think it’s unlikely that you are going to end up with all of your seahorses adopting yellow coloration. Mustangs are normally dark in coloration, displaying brown or black colors more frequently. On the other hand, Sunbursts tend to display the sunset colors, and are most often yellow or orange in coloration.
But, as you know, seahorses are truly the chameleons of the sea with a propensity for changing color in response to a wide range of environmental factors, hormonal influences, and behavioral interactions. The mood of the seahorse is often reflected in the coloration it expresses at the moment. For example, when excited, seahorses typically brighten in coloration, reflecting a state of high arousal. They will often lighten in coloration or brighten up when eating, courting, or greeting, betraying their excitement. On the other hand, seahorses typically darken in response to stress, and fear, anxiety and distress are generally accompanied by dark, somber hues.
So, I suspect that you may see your ponies displaying a variety of colors in the long run, although it’s likely that some of them will always them will always have dark brown or black as their base coloration, while other members of your herd will display various shades of yellow and/or different shades of orange coloration. Altogether, that should make for an attractive group of seahorses with varied coloration at any given moment.
Best of luck with your outstanding herd of horses! I’m sure you will find them to be pretty ponies regardless of any transitory color changes they may display from time to time.
Pete Giwojna, Ocean Rider Tech Support