Ok but can i change the color to Void with a particle?

im not really sure, /lp 0 wildslash and change the particle if you feel like

oshi nice prices wild i would like to buy but i need textures atm =\ GL

You can't change the color of this flame with a particle , this only works on black flame.
If you have a flame particle you will can recolor this one to green (If the flame particle is blue , because Orange+blue = Green) , to some others colors too .
Just try some different colors.^^

Yes you can change the color of this flame if you need help pm me i will make you a particle art to change the color to the one you want sadly i don't think it can be painted black but yeah i can work other colors.

Yeah you can, but not to black. Because the particle is an invert of what will appear in the game, and black inverts to white but white is generic color.