I reformulated my question entirely. So here we go again ;-)
Lets say my goal is to imitate (parts of) the "sunset/sunrise happening" with or within a digital device. I want to transport that feeling to the user.
Can this be done by light only? Which frequency spectrum within the visible electromagnetic spectrum would I have to use (on a screen, with a bulb, ...)? Would users then be able to distinguish between sunset and sunrise?
And will the light its self be enough?
Philips Wakeup Light use case is to wake up their users from sleep. My use case is to motivate people (in offices) who start/end work very early/late (during winter when its dark) or to help people get over a jet lag for example.