The colours as it has been said above. But it can be noticed in almost all pics with Mosquito that the colour was because of the colour bulbs. The lampshades were made of the clear glass.
The streamline fairing is clear but the lens covering the lamp is coloured.
This is a typical RAF wing nav light installation (Beaufort)
The actual lamps are shown below - the "Head" lamp was also used on the wing tips on the Beaufort. From the Mosquito wiring diagram the Mosquito appears to use the same configuration. For information Formation lamps are also called Resin lamps.
The lenses (or in this case bulbs) look blue with the light off. However, with the ligtbulbs having a yellow (warm) cast, when turned on they look green. Remember the old Zip-Loc bag commercial "yellow and blue make green?"