I am new to Smartthings and got my v2 hub a few weeks ago. So apologize if this has been discussed/shared before. On Windows Phone Smartthings app you cannot set the color temperature for Osram lightify A19 bulb, so I modified the device type. Changed the temperature slider to take values between 0 to 100 instead of 2700 to 5600.
https://github.com/asishv/smartthingsv2/blob/master/devicetypes/OSRAM_Lightify_DeviceType.groovy