The problem with the blue depends on the quality of the LEDs.
For anyone that didn't know: they work by having a Blue LED
covered by a flourescent material that glows white when you shine blue light on it. Just like in flourescent tubes.
On chepaer LEDs too much of the blue gets through and they look too blue. Things are getting better these days. Some cars use LEDs as standard for the front lighting, including some using LED
headlamps. So they are not illigal (MOT failures) just by being LED
However, the LED
lamps should technically be E marked which I bet they are not, and the lights were E approved with E marked incandescant lamps, so not sure where that stands either.
That all said, I do think they look better, particularly with Xenons.