Looking good Turbo! Try painting your fire on a new layer and play with the layer effects like screen, hardlight, overlay. I tend to use a few layers to get the right effect =)
What Gill said, or color it in a shade of orange, and give it a transparency, like 50 or 60%, maybe.
Smudge!! 
I'd do what Rowrsie says.
Paint a blob or two of orange on a seperate layer, maybe throw some yellow in the center... then smudge it upward.
"City of Heroes. April 27, 2004 - August 31, 2012. Obliterated not with a weapon of mass destruction, not by an all-powerful supervillain... but by a cold-hearted and cowardly corporate suck-up."
[ QUOTE ]
I'd do what Rowrsie says.
Paint a blob or two of orange on a seperate layer, maybe throw some yellow in the center... then smudge it upward.
[/ QUOTE ]
...And then change the layer to "Screen."
Just be sure you have a background color other than white, though, because a layer set to Screen won't show up where there is white behind it.
Also, playing around in the layer's properties may help. Like giving it an Outer Glow and an Inner Glow... Go wild! Have fun!
thanks for all the advice guys I'll see what I come up with.
I've completed coloring the flats for the Red Kite piece by RogueRider, but I need some help with the flame effects.
Red Kite Color WIP (sketch/ink by RogueRider)
Any advice or linked tutorials would help. I'm using Adobe Photoshop 7.0