Black or any dark colour is OK but make sure you keep your lights on all the time.
A friend has fitted daytime LEDs in the side lights of his +8 which are wired to be classic sidelight brightness at night.
Simple but effective.
But! Choosing the colours of a Morgan's interior and exterior is the hardest and most pleasurable part of the purchase. Using TM's photographs helps, but basically searching Morgan images on the net helped me. And I still keep finding colour combinations I like.
