Action: LabSat Curve Set
		Make Layer Set
			Using: layer
			Name:  “Lab Colour”
		Make adjustment layer
			Using: adjustment layer
			Type: curves
			Adjustment: curves adjustment list
			curves adjustment
			Channel: b channel
			Curve: point list
			point: 73, 0
			point: 182, 255
		Set current layer
			To: layer
			Name:  “b - blue<>yellow”
		Make adjustment layer
			Using: adjustment layer
			Type: curves
			Adjustment: curves adjustment list
			curves adjustment
			Channel: a channel
			Curve: point list
			point: 73, 0
			point: 181, 255
		Set current layer
			To: layer
			Name:  “a - green<>magenta”

This is a little over the top, but if I use "Lab Sat", 
rather than CurveMeister, I want as much control as possible
without having to move the curves by hand.  One is spoilt using
CurveMeister as it is so easy to alter the gradient of the curve.

So alter the Opacity of the Set to reduce the effect.
Alter the Opacity of the layers to reduce the individual channels
and use BlendIF to quickly alter the green/magenta, blue/yellow
ratios!