I need sprites for rocket exhaust that would look exactly like the vanilla one, except all the fiery parts (fireball sprites) to be in cyan tones. Don't change the smokey parts, please. Thanx in advance.

Why not do it yourself? Are you unable to find similar color tones except in cyan and change it yourself or are you just really lazy?

Well, I'm a bad drawer, and it's a pain in the ass for me to recolor them pixel-by-pixel, and the Photoshop color replacement tool works only in RGB Color mode, which CC doesn't accept. I've tried to re-convert it to Indexed colors mode, but it looks crappy if this is done.

Also, since the majority of us are working with the same tools as you, we'd also have to recolour the flames just the same tedious way you would, and none of us have any particular vested interest in it. Mods take time and work if you're putting in all the superfluous detail, which this probably counts as.

Not trying to be aggressive, just trying to be plain about the situation. Unless you give people some reason to do this, or some evidence that their effort won't be wasted (ie proof that you've actually got most of the remaining mod-work done), they're probably not going to recolour this for you.

OK. Guess I'll have to do it pixel by pixel.

No; convert them to RGB, do your color manipulation, then convert back to CC's palette