First, to someone who doesn’t know what the backdrop looked like, the colors in this look really great at first glance - great skin tones!
To improve the accuracy:
Since this is a TIFF, make sure that you do NOT white balance prior to conversion (it’s hard to tell, but it looks like you set a custom white balance prior to converting, when you should just leave it at 0). The pre-conversion white balancing is a step that is only necessary for RAW files, and will cause cyan color casts in tiff files
You may need to adjust your scan settings in EpsonScan 2 to reduce the saturation. When you are scanning as a positive, EpsonScan will add saturation (assuming it is just a regular, positive image). So you either have to reduce the saturation coming out, or there was a “no corrections” option in the original EpsonScan that would leave it neutral.
The white of the eyes is white which hints at the right color lighting/balancing. If I had to remove the color of the background, I’ give It a try with the tools in Lightroom.