a) if you are lucky enough have a third sample point ( for a grey in the photo like a solid mid-grey cloud, or a grey jumper or something ) add and adjust that middle point , so that the read out in the info is equal, (it may not be a perfect mid-grey but it helps) b) if you don't , don't click OK, just yet, see the drop down menu, for curves, go to the RGB option... and (if you feel the need) lighten he mid-tone . like I did in the example,