@Yatothe window class is in RPG Core "Window" it's a class who behavior if I remember ALMOST like the sprite classes
Window.prototype._createAllParts = function() {
this._windowSpriteContainer = new PIXI.DisplayObjectContainer();
this._windowBackSprite = new Sprite();
this._windowCursorSprite = new Sprite();
this._windowFrameSprite = new Sprite(); // <-- it's what you need to setup : it's called as a sprite.
this._windowContentsSprite = new Sprite();
this._downArrowSprite = new Sprite();
this._upArrowSprite = new Sprite();
this._windowPauseSignSprite = new Sprite();
this._windowBackSprite.bitmap = new Bitmap(1, 1);
this._windowBackSprite.alpha = 192 / 255;
this.addChild(this._windowSpriteContainer);
this._windowSpriteContainer.addChild(this._windowBackSprite);
this._windowSpriteContainer.addChild(this._windowFrameSprite);
this.addChild(this._windowCursorSprite);
this.addChild(this._windowContentsSprite);
this.addChild(this._downArrowSprite);
this.addChild(this._upArrowSprite);
this.addChild(this._windowPauseSignSprite);
};
here the code who actually show the reasoning I'm trying to tell you :
SO you can actually chan ge the opacity of it AND the color like it's was a regular sprite //rmwforums.s3.amazonaws.com/emoticons/default_smile.gif
if you are still confused check how they handle the change of tone for the back here the code //rmwforums.s3.amazonaws.com/emoticons/default_smile.gif
/**
* Changes the color of the background.
*
* @method setTone
* @param {Number} r The red value in the range (-255, 255)
* @param {Number} g The green value in the range (-255, 255)
* @param {Number} b The blue value in the range (-255, 255)
*/
Window.prototype.setTone = function(r, g, b) {
var tone = this._colorTone;
if (r !== tone[0] || g !== tone[1] || b !== tone[2]) {
this._colorTone = [r, g, b];
this._refreshBack();
}
};
if you are still confused I will gladly check a more in dept look in that c: