After you buy a flame, like from marketplace for instance, can you change the color of it?

if its black you can using a flame particle texture. but the color is the negative of the pic in game. EX: white in the texture turns black in game

To recolor a flame you need the flame particle texture item, but it works only for dark flames (void, azurite etc) I believe.

Oh well, ninja'd

More specified...

If you have a black flame it's easy to recolor, you make the particle the color you want and invert it (The color that is).

I.e. If you want a green flame, you make the particle texture green, and then invert the color.

Gimp: Color>Invert

Photoshop: Image>Adjustments>Invert, will invert the highlight-midtone-shadow

If you have a different colored flame to begin with, things might get a little more difficult.