Light colour

White light has a different colour rendition than standard headlamps. The spectrum of acceptable white light is broad compared to halogen lamps. It is therefore normal for there to be some variation in colour rendition between the right and the left headlamp. An HID lamp that is at one end of the normal spectrum can have a completely different colour rendition than a lamp at the other end of the spectrum. Colour differences are completely normal. Only replace the electric arc lamp if it has clearly stopped working.