Ahí va un ejemplo sobre la propiedad ‘blendMode’.

Esta propiedad afecta a la apariencia de un movieclip cuando se encuentra en una capa superior que otro objeto en la pantalla. Existen 14 modos “normal”, “layer”, “multiply”, “screen”, “lighten”, “darken”, “difference”, “add”, “subtract”, “invert”, “alpha”, “erase”, “overlay”, “hardlight”.

He modificado el ejemplo de la ayuda de flash y lo he pasado a actionscript 3.

Ver Ejemplo>>
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Este es el código de la clase Main.

[ftf w="640" h="230"]/* Main.as */
package {
import flash.display.MovieClip;
import fl.controls.Label;
import flash.utils.Timer;
import flash.events.TimerEvent;
import flash.geom.Matrix;

public class Main extends MovieClip {

var mc1:MovieClip = new MovieClip();
var mc2:MovieClip = new MovieClip();
var blendLabel:Label = new Label();
var blendModeIndex:int = 0;
var modes:Array = ["normal","layer","multiply","screen","lighten","darken","difference",
"add","subtract","invert","alpha","erase","overlay","hardlight"];

var timer:Timer = new Timer(1000);

public function Main() {
blendLabel.text = “”;
blendLabel.x = 80;
blendLabel.y = 25;
this.addChild(blendLabel);

mc1.x = 32;
mc1.y = 50;
this.addChild(mc1);

mc2.x = 65;
mc2.y = 83;
this.addChild(mc2);

fillClip(mc1, 0x00AA00, 0x22FFFF, 100, 100)
fillClip(mc2, 0xFF0000, 0x2211FF, 100, 50)

timer.addEventListener(TimerEvent.TIMER, changeBlendMode);
timer.start();
}

function changeBlendMode(e:TimerEvent) {
mc2.blendMode = modes[blendModeIndex];
blendLabel.text = modes[blendModeIndex];
blendModeIndex++;
if(blendModeIndex == 14)
blendModeIndex = 0;
}

function fillClip(mc:MovieClip, color1:Number, color2:Number, alpha1:Number, alpha2: Number) {

var spreadMethod:String = “reflect”;
var interpolationMethod:String = “linearRGB”;
var focalPointRatio:int = 0.9;
var matrix:Matrix = new Matrix();
matrix.createGradientBox(100, 100, Math.PI, 0, 0);

mc.graphics.beginGradientFill(“linear”, [color1, color2], [alpha1, alpha2], [0, 0xFF], matrix,spreadMethod, interpolationMethod, focalPointRatio);
mc.graphics.lineStyle(8,0×888888,100)
mc.graphics.moveTo(0, 0);
mc.graphics.lineTo(0, 100);
mc.graphics.lineTo(100, 100);
mc.graphics.lineTo(100, 0);
mc.graphics.lineTo(0, 0);
mc.graphics.endFill();
}
}
}
/* Main.as */[/ftf]