Here are my observations on the "as a PC" entry.
First, it doesn't really belong with "Monsters as a Race" as it has no native hit dice as a PC. All of its hit dice come from its character levels, so it is definitely a "normal" PC race. So, I do agree with that approach. (Plus, there are already several stand-alone PC races. Another isn't going to hurt.

)
Now, some questions:
- Why the two point strength loss if they aren't properly hydrated? I recommend the loss be constitution instead. Plus, what happens if it gets to zero? I assume they die, but it should be stated.
- When talking about the "vibrant colors", that really means non-green, correct?
- Why can't the "vibrant colors" be thieves? Sure, in theory, they might take a hit on "hide in shadows", but I don't see why it would affect any of their other abilities. I grant it isn't that big of a deal, but it seems like an unnecessary restriction.
- What class do the yellow/aristocrats take? I assume fighter, but it should say that.
- I do like their other special abilities, like the poison saving throw bonus and the leaping charge. Those are cool.
- You provide their height; what is their weight and how long do they live?
- The height is highly variable: 3.5 feet to 6 feet. Give a little more description here. From the monster entry, I would assume the rare 2-3 HD leaders would be the ones larger than the typical 3.5-4 feet. But how does it work with PCs? And is my assumption on the monster entry correct? You could restrict the taller individuals to the Yellows and Reds if you'd like. (I.e. Greens and Blues are the typical 3.5-4 feet, Reds are 4-5 feet, and Yellows are 5-6 feet. As an example.) But it'd be good to have some guidance on that. (Unless it is intended to be left to the GM.)
Nice race that seems to be pretty in-line and compatible with the others.