We appreciate your interest
@Rattenkind. Probing the 'terrain' ahead before commiting is certainly wise of you.
However, the community usually discourages new members from getting into something as involved as species/faction creation in our setting before they've had the chance to experience it for themselves. On one hand, taking some time to stew and experience SARP as it is would give you better insight into what would better belong in said universe. Another consideration is avoiding turning part of the roleplay into something more tailormade by the new member - the subtext of that is generally found rude (like putting salt in a meal someone made for you before having tasted it). Also, while we want to welcome as many new members as possible, it's an unfortunate reality that some come-and-go, abandonning anything they created in the setting, and then this largely unattended content ends up bloating the setting and the admins typically have to clean up afterwards (the in-house term is "exfoliation") in order to offer a more dynamically streamlined setting for our participants.
So, we usually tip-toe around the issue. It's a mix of "please no" but also "please don't leave we still like you!". Well-worded members can sometimes reach compromises. In hindsight... some pay off, others less so.
With that disclaimer out of the way... there's nothing wrong with you thinking about something you'd like to introduce later. However, pay in mind that the premise you've offered is yet another human-descended subrace... and SARP has no shortage of those (and, if I'm not mistaken, we were trying to tone it down). We have independent worlds around and there's an effort to establish those, so, establishing a locally different ethnic group of humans with a different color palette sounds feasible. But that feels like it would all there would be to them as far as interest factor goes. I feel that if it is not alien and just culturally different, it would be best to portray them as such.
To me, this wouldn't be a race submission so much as the description of a human colony on in an independant star system. If you want to push this further, you're likely to meet harder questions like "how would this addition help improve the setting?" and usually in human-like races, it's little. It'd amount to yet another human-looking alien-of-the-week we got to see on a Star Trek episode. That's actually what the image you linked reminded me of.
If you go and manage to craft an actual alien race, you're likely to get more traction. This is a tough act because playable races usually end up being humanoid anyways, and non-humanoids are typically NPCs. As it is, the only
true alien race (in my opinion) that SARP has are the
Mishhuvurthyar; though even then, the alieness is stymied by those handling them being humans (Mishhu labeling is alphabetic, which is nonsensical of aliens to use).