To contribute an underlying question of your question: how to "stand out" as cyclist in the dark when from the point of view of a driver's mirror (it's a bit too long to be written as comment, and may be of interest).
In some countries (at least France and Belgium), the front light of a bike light can be white or yellow. If yellow lights are legal in the UK, it can also be a solution, as a single yellow light is more likely to be noticed than "another white light".
During my last stay in the Netherlands, I also noticed that a significant amount of bikes have front lamps (white) mounted on the fork, on each side. It also creates a distinct visual signature, that is clearly distinct from a car one.
