CODE EXAMPLE FOR JAVASCRIPT

phaser set alpha

  preload ()
    {
        this.load.spritesheet('diamonds', 'assets/sprites/diamonds32x24x5.png', { frameWidth: 32, frameHeight: 24 });
    }

    create ()
    {
        const group = this.add.group({ key: 'diamonds', frame: 0, frameQuantity: 50, setXY: { x: 32, y: 32, stepX: 14 }});
        Phaser.Actions.SetAlpha(group.getChildren(), 0, 1 / 50);
    }