Light is a very interesting subject.
Very very very complicated. I studied on it some because of reef aquarium lighting.
More yellow/red/white bulbs punch further for lack of a better way to explain what I mean. Bluer bulbs are more noticable and present a better optical picture, but dont punch as far and more prone to scatter and refraction.
Basicly low kelvin temp the further you can see with less picture resolution, the higher kelvin the shorter distance but with more resolution.
So the yellow and blue has a good mix of light to me.
Reason I think it is a good idea.
1. it is strange so it is noticed quickly.
2. yellow is great in the rain, fog, spray conditions that are the most dangerous for bikes.
3. blue give a highly detailed picture of the what I am trying to see, and it looks really cool.
4. yellow is punching further down the road so I can see a few more feet down the road.
5. It makes me happy.
I do not buy the PIAA has a short burn life. I think they are awesome bulbs. The noyka bulbs are great too.