About the only reason I could think of to buy smart lightbulbs would be to suddenly turn all the lights in the house red, and yell "torpedoes in the water, brace for impact!" and that doesn't seem like a strong enough argument. I'd probably only do this 2-3 times a month anyway.
* Turn existing lights into timed night lights that turn on at a configurable brightness when I pass certain motions sensors and then turn off after a timeout (cool/useful when I'm wandering around house at night)
* Similar: Turn existing light fixtures into motion activated on switches (useful for dark staircase)
* Turn lights on in morning and evening when I'm traveling to make it look like the place is occupied if I'm traveling
* Party mode: cool colors shifting in cool ways in the rare event there's a party
* Gradually go from bright white light to softer light as the day goes on in the office, and then stay soft at night to help with sleep
* Turn on in a sequence when people are detected close by outside in the middle of the night to try to scare them off
* Turn a certain color to indicate something being off, like a server offline, water detected, etc.