1. Irrelevant.
2. Can you name a pre-gun powder weapon that was forest green or maroon? Cause there are plenty of those left and right on the field.
You can't wear brightly colored t-shirts and striking surfaces have to have a cloth cover. Those are the only semi-related rules.
That said, on a national level you're legit with it. Some people just tend to make a stink about sword covers. It happens. Make sure it's your locations rule that's followed across the board and not just singling you out. If you come from a place that disallows them, then those are the rules you have to respect. If you have any more questions, feel free to post them in the
Rules Questions forum.
And just to go on record, I think florescent covers are ugly as *.