Sounds like they're in the same boat they would have been if they had just left them all red.
[Texas] House Bill 1717 states than if a fire hydrant doesn't provide an adequate flow of water -- at least 250 gallons per minute -- it must be painted black or covered with a similar-colored sack.
"We're painting them black and we're painting them black to come in compliance with the law," said Pat Allen, general manager of the [Green Valley Special Utility District ].
Allen said all of the hydrants will eventually be painted black to avoid any liability problems, which is upsetting to emergency personnel.
"If you paint them all black, they they all look like they're bad," Emergency Management Coordinator Dan Kinsey said. "So you can't determine which is a good hydrant and which is a bad hydrant.