Martini said:
The green LEDs may not be physically more powerful, but they will be more visible to the human eye. If color rendition isn't important, then the green will serve you well. I find red to be quite useful, myself.
Batman, there's a couple of issues that might explain the discrepancy. The first one is what Martini mentions about our eyes' capacity to preferentially detect certain colors (green being top of the list).
Could you be thinking of one of curse's pics? Unless the pics are taken using the same camera settings I used, the apparent brightness on other picture is not to be trusted for comparison against the ones I took. It's easy to make a beamshot appear dimmer/brighter that it really is. I can tell you that the white LED A2's I had the chance to evaluate were all the same brightness.
I do not know 65535's source of info, but my white A2 is a relatively old A2, and probably isn't using the latest Nichia LED's (which are far brighter than the older Nichia ranks). If SF is indeed using latest rank Nichias, that would explain the difference between my beamshots and newer lights quite simply. The easiest would be to call SF and ask (and I should try to get a latest-gen white LED A2 and take some more pics!)
Finally, there might be a combination of color rendition/depth perception issues that make one color seem brighter/more useful than another.
So, what do you want this new A2 for? That might help decide which color might be more useful.