I can't speak about the product that you listed in a link or about the green versus blue. The idea behind the underwater lights for fishing works like this. Plankton is attracted to the light. Smaller fish come up to feed on the plankton. Larger fish feed on them etc. I don't think the planking is too particular as far as color.
I shot this video a few years back at our dock at Lake tulloch. The fish you see in the video are Shad. They were feeding on the plankton that was attracted to the blue light. Sorry about the annoying music in the video. I had to add it because my friends were talking and dropping F bombs the whole time I was videoing so I needed something to cover up their annoying banter