 				blue = 0.1 + 0.2 * drand48()
 		}
 
-		return UIColor(red: CGFloat(red), green: CGFloat(green), blue: CGFloat(blue), alpha: 1)
+		return UIColor(red: CGFloat(red), green: CGFloat(green), blue: CGFloat(blue), alpha: 0.25)
 	}
 
 	private func renderStroke( context:CGContext, stroke:Stroke ) {

		if stroke.spars.isEmpty {
			return
		}

		if !_debugRender {
			stroke.fill.set( self.backgroundColor )

		}

		var shapes = UIBezierPath()
		var cp:ControlPoint = stroke.spars[0].a

		shapes.moveToPoint( cp.position )
		for i in 1 ..< stroke.spars.count {
			let ncp = stroke.spars[i].a
			shapes.addCurveToPoint(ncp.position, controlPoint1: cp.control, controlPoint2: ncp.control)
			cp = ncp
		}

		cp = stroke.spars.last!.b
		shapes.addLineToPoint(cp.position)
		for var i = stroke.spars.count - 2; i >= 0; i-- {
			let ncp = stroke.spars[i].b
			shapes.addCurveToPoint(ncp.position, controlPoint1: cp.control, controlPoint2: ncp.control)
			cp = ncp
		}

		shapes.closePath()
		shapes.fill()

		if _debugRender {
			UIColor.blackColor().set()
			shapes.stroke()

			var spars = UIBezierPath()
