Banding is a really big thing! I always call it the most complicated fundamental, since it's diificult to explain the concept itself, difficult to explain why exactly the phenomenon is a bad thing, and the fact that it's easily caused by doing doing normally-sensible things like anti-aliasing.

Color in this piece is a bit of a trick. Khakis are a generally beige color that tends toward green in the shadows. Given that you're already alloting new colors for the pants, you might as well just lead them down toward a slight green. The real trick with color in this piece is that the background you're working over is more saturated than most of the colors you're using, so any work with dark or low-contrasting colors is going to be fighting an uphill battle for the eye's attention.

To demonstrate some color difference (and also some other edits, I was having fun with it), I did an edit:

Hopefully that demonstrates some of the color ideas you were looking for!

Ah! Thank you so much yet again for your valuable feedback :D I'm going to have to spend a bit wrapping my head around that lol but thus is the complications of attempting improvement. I'm going to specifically have to look into banding. As well, should the pants lean towards either the blue or red in the skin/hair and hoody? I did indeed struggle with settling on a color for the pants, they're meant to be kinda kacki(spelling??) Colored 

In general, this is cool, it definitely exudes a retro feeling. You've got a couple pixel-level things though.

There's a LOT of banding across the upper half of the jacket. Especially if you look at the region around where the hood meets the shoulder and the shirt that's showing through there's a lot, in addition to banding on the shading on the breasts and arms. It's mostly cause by a reliance on 45-degree angles and then AA-ing them, which is rarely a good idea despite how it seems totally logical.

I think you may have gone a bit overboard on the AA on the face. It has a bit of that pillow-y look to it. It's causing the crisp lines of the features and outlines to look kinda blurry.

You're gonna need more contrast with that intermediate shade on the pants, it totally blends into the blue-green shadows.

The hair is ambitious, and I like that. A coupel things that might improve it is less of a reliance on your hard outline color to distinguish between hair strands and refining the curves to avoid jagged or misshapen curves (such as the one that extends furthest downward).

Looks really amazing. I really like the poise.

Thank you! I'm quite liking it and having fun with it, I might have to keep at it and try to develop it :D 

Hey nic style!!