Adjusting raw photos in photoshop before importing?

For context, I am trying to generate quantifiable colour measurements to include in linear models, to see whether variables affect colours of my subjects. I am using subjects that are mainly dark with small brighter-coloured dots.

The subjects of my pictures aren’t bright enough, so while the image in general is well-exposed, the subject isn’t. Can I adjust the exposure/contrast/highlights of the raw file in photoshop first and save it as a .TIF file, then generate a Multispectral image in MICA by importing it as a “Linear Image” and measure the visible normalised RBG (which I would then use as response variables in my models)? Will this adjustment of the exposure/contrast/highlights affect my results? Is this even necessary? Does the selecting of grey standards automatically correct for problems with exposure in the image?

Thanks in advance for your help!