Philips Hue light bulbs use a Bridge(transmitter) to connect between your network and their smart lights via a ZigBee protocol called Light Link. Can you control the lights directly with your own xBee radio?
I'm most interested in creating my own custom mechanical dimmers and tactile buttons, switches, levers, etc!
Osram Lihgtify and Cree bulbs apparently use Light Link over xBee as well.
Best Answer
No you can not. The Hue network is a ZigBee Light Link network, and a ZigBee Light Link Network uses "secret" ZLL security keys. Home Automation networks use public security keys, and hence if this was a Home Automation (HA) profile network then you could do this.
The Hue Lights will join a HA network, so if you can create a HA coordinator and reset the Hue Lights then they will connect to your HA coordinator and then you can bind standard HA dimmers etc. You can do all this with the TI ZigBee HA gateway (based on beaglebone), from here: http://www.ti.com/tool/CC2531EM-IOT-HOME-GATEWAY-RD
The challenge would be to reset the lights and get them to join the HA gateway, you could use Lampsteeler, but timing would be tricky as the light "may" just join back to the Hub.
After the Lights have joined the TI HA Gateway you can play around with the HA Gateway UI, there is a bind option which you can use to "bind" a HA switch to the Lights, I have done this already so know it works. but you loose the ability to control the Lights through the Hue App as they will no longer be connected to the Hue Hub... Unfortunately there seems to be no way to make the Hue Hub join a HA network, although the ZLL spec states that this must be possible.