Retrieve the manual white balance color temperature
camera_error_t camera_get_manual_white_balance(camera_handle_t handle, unsigned *whitebalancevalue)
Use this function to retrieve the current manual white balance color temperature. If no white balance value was set, a default white balance value is returned. To see how to set the white blance, see camera_set_manual_white_balance().
The viewfinder must be running before calling this function.
CAMERA_EOK when the function successfully completes, otherwise another camera_error_t value that provides the reason that the call failed.