First of all, some serious GP kudos to you and your team for testing it with the camera, even though you didn't think it should have been a problem. Looking at the robot, I wouldn't expect it to be a problem, either.
Personally, I would expect teams that are planning to use cameras to have put at least a bit of effort in to calibrating them. If you can demonstrate that a calibrated camera can reliably track the green target material without interference from your robot, then you should be fine.
After all, teams are expected to be gracious (not attempt to "jam" the system) and professional (follow proper equipment set up). R02 prohibits intentionally interfering with the vision system, and your colour scheme is clearly not intended to interfere, and this Q&A
http://forums.usfirst.org/showthread.php?t=11118 suggests that teams are expected to calibrate their cameras. This Q&A
http://forums.usfirst.org/showthread.php?t=11423 suggests that the test is "large areas the same colour" as the vision target. I would suggest that your robot niether has "the same colour" nor "large areas" of that colour once additional components such as bumpers, etc. are added.
Note, however, that I say "should" and "I expect" a lot. If a more detailed search of the Q&A doesn't answer this question to your specifications, then I would suggest either posing a question on the Q&A along the lines of "Regarding R02, is the determination of "same colour" as the vision target to be made by a) a tech inspector based upon how the human eye perceives colour B) an uncalibrated camera C) a calibrated camera or D) some other technique?" That might answer your question.
But for now, I'd leave it green, and take along a roll of 2" wide masking tape to your competition so you can cover it up if you have a problem.
Jason