Thank for comments. This was my first flame painted but really tried to do it with reference to real flamethrowers (example: http://fafel.net/temp/flame.jpeg ) where sequence of colors is more or less such as I did. The problem was 'the ball' on the end which rather doesn't exist in real environment and I painted it just like PP staff.
Looks good, but the flames are backwards, fire should be white/very light yellow in the middle (hottest part) and darken to red on the outside, which is counter intuitive to regular shading highlighting.
The OSL is great, looks subtle enough to not steal the attention, but not too subtle so that it can be missed.