Just thought I would report here in case anyone is searching for Zigbee 3 RGB+CCT LED bulbs to integrate with OpenHAB.
I bought a bunch of these (E27 & E14):
They worked like a charm first time. 
I can control RGB colour, white temperature and intensity with no issues at all.
My controller is a ZB-Stick, which is just a rebranded Elelabs ELU013.