Hi,
Similar ideas, for LEDs, not thought about details or implemenbility much..., what about dividing down AC phases, and isolating with optocouplers, then:
a) quad comparator, three triggering on zero crossings, fourth resetting other two.
b) three 555s as one-shots triggered by falling edge of sine waves and outputs lasting e.g. 333ms, lighting LEDs momentarily at least, using third 555 to reset the other two maybe, or a bjt with CR on base to deliver short reset signal.