[ArrogantBustard]

They mean "gray". The tape has microscopic retroreflective crystals embedded in it. It looks gray in diffuse lighting. Shine a bright white light on it (like an automobile headlamp) and it is as bright as any mirror, though does not form an image.

[Willie Green]

The tape has microscopic retroreflective crystals embedded in it. It looks gray in diffuse lighting. Shine a bright white light on it (like an automobile headlamp) and it is as bright as any mirror, though does not form an image.

Sounds like one of Liberace's sequinned suits.
I can't picture them going for that, day-glo orange is simpler, IMHO.