I mean the only explanation I can come up with logically is it is supposed to be reminiscent of Savage Opress why would they be yellow/light orange anyway. Another possible explanation that you kinda hinted at was the ranking. Perhaps they are somewhat of a high rank within the super commandos but I ask myself then why Saxon isn't that yellow/light orange color. Maybe It all boils down to preference. As we see in earlier models some of the former Death Watch Mandalorians welded zabrak-like horns to their helmets as a sign of respect. I don't know though they look extremely cool and I wish to see more of them.