I was once asked at a University PPE interview, Does time have a colour? I found it both extremely interesting and baffling. My opinion was that as time was not a physical property it could not have a colour yet I questioned myself countless times. What's your opinion - could time have a colour? K(17)

I am unsure exactly why you found this either interesting or baffling. It seems clear that what makes things colored is their tendency to reflect or otherwise emit certain sorts of light. Time doesn't do that, nor could it. As an uncolored phenomenon, time has plenty of company, including space, music, the square root of two, and philosophy. Now, someone might associate time with a color. People do, after all, report strong "cross-modal" associations between smells and sounds, or tastes and colors. Such a person might describe time as cobalt blue, or as tasting like a turnip. But I think we would be wise not to regard their claims as literally true.