I was playing around with a dried up piece of Christmas cactus (theyre not called leaves, cladodes I think is the term), and normally i use a white card as a background, covering the hole in the base completely as I dont use the condenser , but I turned the card over and it was bright red! I then tilted the lamp so that most of the light was going under the 'leaf' and hitting the red card. The light then bounced off the card and back through the semi-transparent specimen.
Some of the light from the lamp was hitting the top surface and thus allowing some green to show.
Both 40X
And a shot of the aereole complete with a few tiny spines, at 200X

Canon 5D and 30D | Canon IXUS 265HS | Cosina 100mm f3.5 macro | EF 75-300 f4.5-5.6 USM III | EF 50 f1.8 II | Slik 88 tripod | Apex Practicioner monocular microscope