Problems can occur with Amber bulbs depending on the quality, the coating can crack and even fall off mixing white with the Amber light overall reducing the Amber content.
Tarka has amber bulbs and clear lenses, as fitted by the factory.
I've never felt they were either dim or just a point of amber light.
As a result of this thread I took the cover off the O/S front one.
The amber coating is starting to crack and there is no reflector, just the metal of the light fitting.
So, I'll buy a bottle of amber clear lacquer and re-coat the bulbs and also polish the metal back plate on the fittings. Even better would be some reflective plastic sheet from which I could make retflectors!