In general, this is actually a very good piece. The shape is nice, the chest isn't as pronounced as many make it, and the stomach looks like a normal cats (a common mistake when drawing cats is to make them to skinny.)
The ears are placed nicely, and your tail isn't to unrealistically curly.
I know you're drawing and OC, but the color scheme isn't the best and probably not what you should aim for when drawing a realistic creature. The markings on the legs, back, and hip are defiantly the worst of the markings (She looks like she's tattooed and wearing leg warmers- sorry if you were aiming for this.)
The placement of the legs are nice, but the body is a little to short and the tail looks detached (Bravo on what you did with the gradual transition of black to grey, it actually looks pretty nice) and is a little to fluffy for the rest of the body.
The muzzle is also to long and pointed, and the eyes also look off, they're not really shaped properly.
The markings are way to all over the place.
If you're set on having unrealistic coloration, I would recomend that you try to have the colors on a more limited scale. (Having the blue/pink/green/red transition looks off even if you're aiming for unnatural.) I would recommend something like:
I don't really have anything for green
I would recommend keeping the black/dark grey background for the fur though.