Clear but still yellow

Pass

And so we are going to fail this white position lamp bulb because.............?
Pass

Well I suppose on a technical level you may be able to use adversely affected by another lamp. Other than that, I would say it is incorporated in a yellow headlamp, so if overshadowed by the yellow light so you could not tell it was white then that would still pass. Certainly food for thought though.

Mmmm so if the headlamp is yellow how do you know the bulb is white? The headlamp bulb is white in a yellow headlamp. I'd consider the colour to be testable and not the origin of the colour if that makes sense..

We may have un-covered another area for improvement..

I not sure there is any problem here;

Two front position lamps must be fitted, one on each side and show a steady white light to the front (or yellow if incorporated in a yellow headlamp).

But the original poster said the lamps are white with yellow headlamp bulbs fitted, thus the position lamps being white.