The script switches foreground color to the next color in the "colors" variable each time you run the code.

Circulate foreground color.jsx

#target photoshop

// https://gist.github.com/joonaspaakko/347c270f15bc1d11efe9
var colors = [ "#0033ff", "#9a3838", "#888888", "#a6ad1e" ];

function init() {

	var read = tempFile.read(),
		color = colors[ read ];

	setColor(
		hexToRgb( color ).r,
		hexToRgb( color ).g,
		hexToRgb( color ).b
	);

	var newNumber = read === ( colors.length-1 ) ? 0 : read + 1;
	tempFile.write( newNumber );

}

function setColor( r, g, b ) {

	// =======================================================
	var idsetd = charIDToTypeID( "setd" );
	    var desc25 = new ActionDescriptor();
	    var idnull = charIDToTypeID( "null" );
	        var ref5 = new ActionReference();
	        var idClr = charIDToTypeID( "Clr " );
	        var idFrgC = charIDToTypeID( "FrgC" );
	        ref5.putProperty( idClr, idFrgC );
	    desc25.putReference( idnull, ref5 );
	    var idT = charIDToTypeID( "T   " );
	        var desc26 = new ActionDescriptor();
	        var idRd = charIDToTypeID( "Rd  " );
	        desc26.putDouble( idRd, r );
	        var idGrn = charIDToTypeID( "Grn " );
	        desc26.putDouble( idGrn, g );
	        var idBl = charIDToTypeID( "Bl  " );
	        desc26.putDouble( idBl, b );
	    var idRGBC = charIDToTypeID( "RGBC" );
	    desc25.putObject( idT, idRGBC, desc26 );
	    var idSrce = charIDToTypeID( "Srce" );
	    desc25.putString( idSrce, """photoshopPicker""" );
	executeAction( idsetd, desc25, DialogModes.NO );

}

// https://gist.github.com/Arahnoid/9923989
/**
 * hexToRgb
 * @param  string  hex  Hexadicimal value
 * @return number       Color of selected chanel Red, Green or Blue
 * @usage  //alert( hexToRgb("#0033ff").g ); // "51";
 * @usage  //alert( hexToRgb("0033ff").g );  // "51";
 */
function hexToRgb(hex) {
	var result = /^#?([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i.exec(hex);
	return result ? {
		r: parseInt(result[1], 16),
		g: parseInt(result[2], 16),
		b: parseInt(result[3], 16)
	} : null;
}

var filePath = (new File($.fileName)).parent + "/Circulate foreground color tempFile.txt",
tempFile = {
	write: function( color_number ) {

		var file = new File( filePath );
		file.open('w');
		file.writeln( color_number );
		file.close();

	},
	read: function() {

		var file = new File( filePath ),
			color_number = "",
			fileOpen = file.open('r');

		while( !file.eof )
			color_number += file.readln();

		file.close();

		return !fileOpen ? 0 : parseInt( color_number );

	}
};



init();