Another vote for the Phillips Hue system. I’ve four of the colour bulbs and one of the white bulbs, although I will admit I don’t play around with the colours very often.
They integrate well with HomeKit and seem to be the best supported system with third party apps. The sleep monitoring app I use (Sleep Cycle) integrates with them to simulate a sun-rise before the alarm goes off so as to help wake you up gently.
I’ve setup an alert on Camel Camel Camel to email me when the prices of the bulbs drop on Amazon and add an extra one when the prices are low.