4 ms·
In the UK it was mixed. Different people made the coloured glass lenses, and some of the manufacturers had more blue in the lens. This was an attempt to colour
by DanBC 6y ago
In the UK it was mixed. Different people made the coloured glass lenses, and some of the manufacturers had more blue in the lens.
This was an attempt to colour correct the yellow light given off by some incandescent lamps.