Re: White Balance Dilemma
You say, the stage lights are 3200, that's a warm yellow color. Illuminate a scene by such light and everything gets a yellow cast.
A custom WB set to 3200 will make your camera add a lot of blue to the whole image, to neutralize this yellow cast.
The problem with the magenta spots is that they should not be corrected like this. They are magenta and not really colored by the yellow stage light. Yet, the WB 3200 setting will make them blue like everything else. That's what you see in the first photograph.
The difficulty of your example images is that they are so different. As the originals are RAW, why not pick one, set the color temperature to 3200 and 7700 resp. and export both results?
I believe a scene like this is very hard to get perfect with just one WB setting. There are multiple, differently colored lights, so everything is colored by some mix of yellow, blue, magenta and whatever color.
The best advice is to just use a fixed WB setting and correct in LR or CR by the WB sliders until it looks good. Some local correction may be necessary though.
Gerald Bakker - Home