I have ultra bright front light that remains on fixed at night and in low light I switch it to flashing, On the back of my bike I have my old faithful rear light Ive had for over 10yrs, its bright good on batteries and has nice strobe like flash on it and all so use
proviz rucksack which has large triangle EL on the back plus it reflective bits all over it. Since Ive started using the rucksack Ive notice a lot more people holding back and being given lots of room while over taking. I think a bluish white flashing triangle makes them think WTF is that !!!