This is my favorite pet peeve, whether bikes or cars are concerned. I simply refuse to ride or drive a bike or car with red amber turn signals. If I buy such a vehicle, I promptly modify it or retrofit to amber rear signals, as I have done once on a Chrysler minivan I once owned.
The British folks on this forum are probably aware that, in the UK, in order to pass the MOT inspection, no red signal lights are allowed, only amber. The worst possible iteration of that is in American vehicles that have the idiotic combination rear red brake light/turn signal arrangement. Once that bulb blows, you loose both the brake and turn signal at the same time. Sadly, this design is also on the latest models of US Harley Davidson Sportsters, to keep up with side lights fashion.
American military members bringing their US-spec cars to the UK that have red rear turn signals have to be modified to amber to comply with the MOT. My daughter's Honda Civic still has that mod after returning from the UK.
A red turn signal flashing light could easily be confused with either the driver pumping the brakes or brake lights working intermittently. As a side note, if you drive by any road construction at night, you'll notice that the flashing lamps are always amber, not red, by DOT requirements.
The amber turn signals design is virtually the standard for world wide vehicles.