create averge color inversion layer using script

@powerful_Zephyr5EF9 

Does the ScriptingListener plugin work with your version of Photoshop?

You will find things much easier if you have it.

Here is a raw SL code recording of the key steps, with some comments:

// Merge visible with duplicate
var idmergeVisible = stringIDToTypeID("mergeVisible");
var desc615 = new ActionDescriptor();
var idduplicate = stringIDToTypeID("duplicate");
desc615.putBoolean(idduplicate, true);
executeAction(idmergeVisible, desc615, DialogModes.NO);

// Blur - Average filter
var idAvrg = charIDToTypeID("Avrg");
executeAction(idAvrg, undefined, DialogModes.NO);

// Invert layer
var idinvert = stringIDToTypeID("invert");
executeAction(idinvert, undefined, DialogModes.NO);

// Set blend mode to color
var idset = stringIDToTypeID("set");
var desc619 = new ActionDescriptor();
var idnull = stringIDToTypeID("null");
var ref176 = new ActionReference();
var idlayer = stringIDToTypeID("layer");
var idordinal = stringIDToTypeID("ordinal");
var idtargetEnum = stringIDToTypeID("targetEnum");
ref176.putEnumerated(idlayer, idordinal, idtargetEnum);
desc619.putReference(idnull, ref176);
var idto = stringIDToTypeID("to");
var desc620 = new ActionDescriptor();
var idmode = stringIDToTypeID("mode");
var idblendMode = stringIDToTypeID("blendMode");
var idcolor = stringIDToTypeID("color");
desc620.putEnumerated(idmode, idblendMode, idcolor);
var idlayer = stringIDToTypeID("layer");
desc619.putObject(idto, idlayer, desc620);
executeAction(idset, desc619, DialogModes.NO);

// layer opacity 50%
var idset = stringIDToTypeID("set");
var desc622 = new ActionDescriptor();
var idnull = stringIDToTypeID("null");
var ref177 = new ActionReference();
var idlayer = stringIDToTypeID("layer");
var idordinal = stringIDToTypeID("ordinal");
var idtargetEnum = stringIDToTypeID("targetEnum");
ref177.putEnumerated(idlayer, idordinal, idtargetEnum);
desc622.putReference(idnull, ref177);
var idto = stringIDToTypeID("to");
var desc623 = new ActionDescriptor();
var idopacity = stringIDToTypeID("opacity");
var idpercentUnit = stringIDToTypeID("percentUnit");
desc623.putUnitDouble(idopacity, idpercentUnit, 50.000000);
var idlayer = stringIDToTypeID("layer");
desc622.putObject(idto, idlayer, desc623);
executeAction(idset, desc622, DialogModes.NO);

It's a bit verbose... You can reduce the code length and visual/comprehension complexity by using the CleanSL script, manually removing redundant variables or swapping out blocks of recorded AM code for standard DOM code. Makes no difference to the execution speed, it's just easier to work with when it isn't needlessly complicated:

// Merge visible with duplicate
var idmergeVisible = stringIDToTypeID("mergeVisible");
var desc615 = new ActionDescriptor();
var idduplicate = stringIDToTypeID("duplicate");
desc615.putBoolean(idduplicate, true);
executeAction(idmergeVisible, desc615, DialogModes.NO);

// Blur - Average filter
executeAction(charIDToTypeID("Avrg"), undefined, DialogModes.NO);
// or DOM code
// app.activeDocument.activeLayer.applyAverage();

// Invert layer
app.activeDocument.activeLayer.invert();

// layer opacity 50%
app.activeDocument.activeLayer.opacity = 50;

// Set blend mode to color
app.activeDocument.activeLayer.blendMode = BlendMode.COLORBLEND;