Bulb detection used to be a big frustration for me as well, but they've 100% resolved my issues with it in the latest firmware update (now a few months old). I'd previously had issues with detection after power-on since WiFi would take ages to connect, but now its down to a pretty impressive 5-6 seconds from cold start and is far more reliable.

Random color changes or flickering sounds like a defective bulb, I'm sure they'd replace it for you if you contacted them.