I thought it legally had to be only white lights at the front apart from indicators, and only red lights on the rear. But who knows thee days I have seen blue, green, yellow on the front and similar on the back also with black tinted lamps. I t is similar to front foglamps which were only supposed to be used in fog or falling snow unless they were two foot off the ground , now they are used in combo with parking lamps and headlamps..
Rant over for the moment.
The white brake light still lights up red @Olliebeak . I think all the white brake lights are aftermarket whereas later model Z3s had white indicator lenses. My 2002 Z3 2.2i Sport had white indicators, but red 3rd brake light from new.
That's correct @gookah , I forgot my 2.2i sport had a white brake light as well as indicators. The 2002 1.9 I had was fitted with a red brake light and white indicators, but I don't know what was original.