i assume you had permission from secretary of the state for the flashing red? even highways agency have to for their vehicles to have flashing red
Believe it or not, under current lighting regs for vehicles, the only light I am not allowed to use is flashing green! Red is not covered by many restrictions, the main one being that it can only face rearward, even blue can be used in the correct circumstances. There is an official list of vehicles which may have blu lights fitted, and it's bigger than you would think, however that covers lights that are blue even when not lit, i.e blue lenses. A light that is clear when not lit, but emits blue light can be fitted to any vehicle, it's how you use it that counts. When I was with the incident support team I had these fitted to one of my own vehicles in case I needed to use it for the job (we ran on their insurance) it was approved by the local traffic division, on a couple of occasions while off duty I came across RTC's and used the blues while parked roadside, I never had any issue with the police.
One time I was with a traffic cop and we were "playing" with each others cars, his only comment on the blue lights was, "I hope you don't use them to get to Maccy's". If used for the right reasons the police don't bother, used to warn at an RTC, or other incident, they are fine, safety comes first.Plus being trained to drive on blue lights, there isn't really an issue, although it would have to be an extreme set of circumstances these days, such as a major medical emergency where it would be quicker and more likely to save the casualty for me to drive to the hospital rather than wait for the ambo.
I used to be well known around the area, the local cops actually said that if they saw the vehicle being driven by anyone other than me they'd pull it, a lone cop at an RTC would often look relieved if I arrived on scene, at one incident the only traffic cop available was on a motorbike, everyone else was tied up with incidents, I was passing the incident on the main road through our village, it was chaos. I pulled over, switched the lights on and proceeded to close one lane, then went on point duty directing traffic while he dealt with the injured. The cheeky bugger left me with the brushing up after recovery had left, as he had another "emergency" to deal with, a local resident had turned up with cups of coffee.
I've dealt with a few incidents round here over the years, the funniest one was when an elderly gent got knocked of his pedal cycle, he kept several large German Shepherds loose in his garden, "go on, you're good with dogs, you go inform his wife" said the cop. I opened the gate and went in without any hassle, only suffering a few wet licks and a coating of dog hairs.
Here's a pic taken from the dashcam at one incident I attended, it was on a lane outside the farm I used to work at.