Xenon light bulb. High Intensity Discharge (HID) headlight D2-S 35W. Low Beam
The white output and the BMW reflector design system, tend to give it a bluish/purple look.
The Xenon bulbs change color with usage & time, hence the reason why one bulb will appear yellow & the other 'blue'.
When replacing the Xenon bulb, both must be done at the same time to avoid different colors.
Part Number: 63 21 7 160 806 / 63-21-7-160-806
Brand: Osram Sylvania