Are you making a graphics update function in newgraphics.c and defining it in powder.h? If you are, try copying a similar function, like the one for heat flame or fireworks, and just modifying the color.

@star400040 (View Post)
In powder.h, there are graphics drawing functions. Create one in the same way as the others, it should look like graphics_xxxx(something). In the ptypes table, find your element, and scroll all the way to the left, past the description. Change the last NULL to &update_xxxx. Then, in newgraphics.c, make that function, just like the other ones in there. Add this:

*firea = 255;
*firer = xxx;
*fireg = xxx;
*fireb = xxx;

*pixel_mode = PMODE_NONE; //Clear default, don't draw pixel
*pixel_mode = FIRE_ADD;
//Returning 0 means dynamic, do not cache
return 0;

If you are creating a gas, it should do something like this automatically, but maybe it wasn't the color you wanted.