This image was taken through the 100x oil objective and a 2x camera adapter projecting the image into a Nikon D7500. The sample is a leaf from one of my plants (Dioscorea elephantipes, but I don't think this picture would look very different for other plant species)
The edges of he leaf were already yellowish brown. Here is a photo of that area with much less chlorophyll:
And here is a photo through the 40x objective using oblique illumination:
If you want to see some really fantastic photos of plant stomata I recommend having a look at Rolf Vossen's photographs here: https://microscopyofnature.com/stomata
I am looking through his documentation trying to understand how he managed to get those images. They are spectacular.
All of my students get pictures like the second one because we don't look at the leaf itself. We use nail polish to make an impression and look at that. It comes out as a monochrome relief.
Took me back to microscopy lessons in 7th grade, tearing leaves just the right way to see stomata. I only ever got results like the second picture though. Is all that green on the first just chlorophyll?
I didn't even need to tear the leaf, I just placed a drop of oil on top and used the 100x objective. The green is from the chlorophyll, yes. I suspect that the cells are so packed with chloroplasts that it just looks smoothly green.