Have applied a simple Hue/Saturation effect to an EXR file sequence in AFX CS5. The controls seem unpredictable. Adjusting the Lightness seems to effect the Saturation. Thanks
And exactly? Sorry, this is far too vague. Provide a frame from the sequence for inspection or screenshots. In any case, I'm getting that magic tingle in my left toe that tells me that the files were rendered with wrong settings in your 3D program, so exposure and the internal value ranges are way off, resulting in the seemingly wrong behavior. Either they are hopelessly over-exposed (all values larger than 1) or your ranges are so small (shortly above zero, but never reaching even 0.5 in float space perhaps) that even tiny adjustments whack them out. There's definitely nothing wrong with the effect...
It was a bit vague.
You did solve it for me though. Awesome!!
I was working in 8bit colour your answer led me to change to 32bit.