I've been trying to find a way to illuminate things when I use my 35mm macro. In different configurations it can reach up to 3x macro but the working distance makes it hard to get any type of flash on the front of the subject.
I started testing different pieces of foam and found firing a small flash straight down into a short foam tube works very well.
The green could have been the color of the foams I was testing or even the LED lamp I was using for focusing. I'm not much for PP so I'll have to give it a try.