MikauKahn: practice old palette challenges, including those. You can then focus on how to use (and not use) color. Should help kill a number of misconceptions and bad habits. The crazier the palette, the better!
Losm: nice, but I wish there was more interesting changes between versions. Color number, contrast, etc.
Study the world.
Got it.
I'll bring my notebook and pencil outside and inspect a piece of grass for hours.
I'll be the best artist ever! >:D
Don't be like me? 
Har... Seriously though, I don't know. I consider myself pretty shitty in colour theory and all that jazz, honestly. I guess just keep making art? Try other forms beside pixel art, of course; try to work with and understand all sorts of different art mediums. Study other pieces, study the world, and see how colours relate to eachother.
I dunno.
Oh, I know you didn't copy. If you compare quality, mine looks like the knockoff XD
So... Care to spare some words for someone who can't choose colors to save his life?
Haha, wow. 
I swear I didn't copy you! I've had this thing in my images folder since August of last year!
Thanks! I kind of easier to find cool looking colours for something abstract like this, I find, though.
This looks oddly familiar... Although it looks much better than whatever vague memory I'm thinking of.
Goodness, how do you choose such good colors?
Thanks Manupix, I'll get right on that after I'm done with my current project.