I was wondering whether there were already Chinese copies of the Philips Hue A19 Bulbs which were compatible with the Philips Hue Bridge as the current price point for ZigBee / Wi-Fi / Z-Wave Color Bulbs is still very high at USD 60 - 90 per color bulb from brands such as but not limited to Philips Hue, LIFX, Zipato, Aeotec.
I ended up with buying and trying out Color Bulbs from the brand Kudled, which is a company with operations in Shenzhen, China.
Note that I am based in Shanghai, China and was able to buy a Kudled Color Bulb for USD 23, still not cheap but significantly more affordable than the closest alternatives at the moment. I personally believe the price point needs to go to about USD 10 per color bulb for mainstream adoption and I expect that this will happen within the next 3-5 years, mainly due to Chinese low-cost suppliers.
So to pair the Kudled Color Bulb with the Philips Hue Bridge I had to turn the light switch on and off rapidly 5 times to get the Kudled Color Bulb in 'ready to pair' mode, which it shows by switching colors from blue to red (note that I found this process out coincidentally and this required step is not indicated in any manual to my knowledge).
Once the Philips Hue Bridge is paired with the Kudled Color Bulb the color result is satisfactory but not perfect as the color specs of the Color Kudled Bulbs are not identical to the color specs of the Philips Hue Bulbs.
Below my test results (the left bulb is the Kudled Color Bulb, the 2 right bulbs are Philips Hue Bulbs):
My personal conclusion is that it is workable to have a color bulbs setup combining Kudled Color Bulbs (or any other ZigBee Color Bulbs brand) with a Philips Hue Bridge, but if your goal is to realize a consistent color experience in a single room I would recommend to stick with 1 brand per room for your color bulbs to avoid awkward color inconsistencies.
Some specs I was able to identify:
Accessible Communication Range：100m
Accessible Network Range：50m
SMD3535 RGB Leds
On a subjective level, if I would personally rate the color quality of Philips Hue A19 Bulbs a 9/10 I would at the moment rate Kudled Color Bulbs a 8/10.