are these any good?

[Phil TK]

I think those purple LEDs stand out superbly against almost anything, I can notice them from miles away in my mirrors and especially when filtering through long lines of traffic. The biking lobbys should be campaigning to make purple lights OUR colour on a legal basis, it might be the solution to standing out against all the white sidelights the cages have on during the day.
Does anyone know a good source for bright purple LEDs?