The Osram lightify line has an RGBW bulb which can be paired directly to the SmartThings hub so you don’t need its own Gateway. That’s officially supported.
https://shop.smartthings.com/#!/products/osram-led-smart-bulb-rgbw
Aeon labs has a Z wave RGBW bulb that also appears directly to the smart things hub. However, like others the way bulbs this is noticeably bigger than a typical bulb, it’s an A21 rather than A19. Same socket but it will stick out of the fixture much further. If you’ve ever seen one of the old three-way incandescent bulbs, it’s that size.
https://www.amazon.com/Aeon-Labs-Aeotec-Z-Wave-Light/dp/B00VQISQW4
There are also some Wi-Fi bulbs. LIFX is officially supported. Good color, very bright, does run hot.
Striimlight is both a speaker and a light, but it’s very expensive at $99/bulb. Could be fun for a teenager’s room and some community members are using it.