Plug a Color Correction texture to the Opacity slot of the VRayLight material, and then link the VRayBitmap output to the Color Correction's input.
Set the Saturation to -100, Brightness to -0.332, and Contrast to 0.332. This removes the undesired black background.
Now let’s make some final tweaks on the VRayLight material.
Enable the Compensate camera exposure option. This way it is easier to find the right values when tweaking the material.
Raise or lower the Color multiplier to make the flames stronger or weaker. In this particular case, let's adjust the multiplier to 3 1.5 to boost the color.
Fancy Bullets
type
circle
Enable the Emit light on back side option so the flames emit light from the back side of the plane as well.
