[dougsmit]

I doubt there is a good answer but would give RAW a chance. Vapor lamps are not continuous spectrum and will never be 'natural' looking. The question is whether you can tweak it to a point that it looks 'good' even though it is not exactly natural looking. White balance assumes there is a continuous spectrum available and gaps in that spectrum make ledges that you have to fight. At least shooting RAW allows you to see the adjustments before you drop the quality to JPG level and also allow combining conversions if you decide you need to make one area a different color than another. Another trick might be to reduce the saturation a bit leaving some color but playing down the fact that it is not the right color.