The top left corner appears to be particularly out of focus. @WilliamW mentioned above to try the method talked about here Comparison of a pi-camera and a 20x optical lens - #9 by r.w.bowman
In regards to color saturation I am curious if substantially better results can be I achieved with a standard set up especially at 100x. I have never done any better than you with color saturation. Your images are overall the highest resolution images I’ve seen yet on OFM.
Most evenly illuminated images I’ve seen (Images were taken at lower magnification):
Not trying to be overly negative, if you achieve much more even color saturation I would love to see how you do it!