"project the image of the jet travelling towards the viewer at extreme speed, the aircraft would appear to be red due to the doppler shift."
I'm sorry to say that this would again make the the 'Blue Arrows' as the doppler shift would be to the blue end of the spectrum as the wavelength of the light is shortened with the relatavistic closing velocity of the objects.
Having said all that, it is a brilliant explanation to why the Rads seem to be at almost every air event at the same time.