Not sure if I agree with the color choice there -- I do like the idea of red used in the clouds for the middle shade, but the hair is now *way* offcolor to what it should be Tongue
Might be too red. Not sure. Red sunset + purple hair doesn't equal purple or blue, but it might not equal red, either. X3
You're right, I am assuming you have five dollars for a mouse, hahah. I can't imagine many life situations that would afford you the leisure of hours of time spent making pixel art to post online, but not a five dollar bill for a mouse. XD
About MS-Paint Vs. Graphics Gale: You say you're not used to Graphics Gale, so you're not using it yet. My advice to you is to learn the program, and then use it from now on. It takes literally fifteen minutes to learn everything Graphics Gale does, and it's much better and faster for pixel art than MS-Paint is.
And I didn't say what you made was outside the abilities of MS-Paint. You could do the best pixel art in the world with MS-Paint. It just won't be as fast or convenient as using a better program, hahah. ^ ^;;
Sorry for the way I worded my last post, though. It made it sound like I thought you were lying about using MS-Paint, when I don't. What I basically meant to say was that you should really look into another art program, because there's not much reason not to. Anyway, here's another edit with the hair color changed:

I still like the first edit I did more, though the newer one may be more accurate to the show. The first one I did looks softer and more sunset-y, though...maybe I just don't like the idea of an orange horse having highlighter-purple hair, hahah. The color combination burns my eyes. XP
Edit: Actually, just grabbed a screencap from the show of Scootaloo sitting down outside on a sunny day, and the color I used for her hair in my newest edit at sunset is *the exact same color.* Which means my older edit actually *IS* more accurate (and better looking, in my opinion), since her hair should obviously shift more toward the red side during sunset compared to her noon-time hair. The color you picked for her hair, for example, is actually *more blue* than her naturally lit hair, which is what my complaint with your color choices were originally - it looks like there's a blue haze over everything.
Anyway, happy pixeling! This piece has improved a ridiculous amount since you started it. ^ ^