it would work but they don't have accurate timing in their internal processors, so the temporal drift would make them do random things as they heated and cooled differently. It only takes a miniscule change at 'megahertz' to multiply quickly into a real distortion.
Would be a bit overkill to use these LEDs and syncronize them by sampling their color.
You can sample its current: at some point it is going to cycle all of leds off - that's when you can synchronize them. It does require two pins per led for this to work.