new ChannelParameters()
};
_setupChannelExclusions(chan);
// build each channel and attach to color node
OperationNode r = _buildNode(1, chan[0]);
OperationNode g = _buildNode(1, chan[1]);
OperationNode b = _buildNode(1, chan[2]);
rgb.setChild(0, r);
rgb.setChild(1, g);
rgb.setChild(2, b);
return rgb;