     }
 
 
-    class func bitmapContext(size:CGSize, origin:CGPoint = CGPointZero, color:CGColor = CGColor.whiteColor()) -> CGContext! {
+    class func bitmapContext(size:CGSize, origin:CGPoint = CGPointZero, color:CGColor = CGColor.clearColor()) -> CGContext! {
 
         let colorspace = CGColorSpaceCreateDeviceRGB()
         let bitmapInfo = CGBitmapInfo(rawValue: CGImageAlphaInfo.PremultipliedFirst.rawValue)


public extension CGContext {

    class func bitmapContext(bounds:CGRect, color:CGColor = CGColor.whiteColor()) -> CGContext! {

        let colorspace = CGColorSpaceCreateDeviceRGB()
        let bitmapInfo = CGBitmapInfo(rawValue: CGImageAlphaInfo.PremultipliedFirst.rawValue)

}

public extension CGContext {
    class func imageWithBlock(size:CGSize, color:CGColor = CGColor.clearColor(), origin:CGPoint = CGPointZero, block:CGContext -> Void) -> CGImage! {
        let context = bitmapContext(size, color: color, origin: origin)
        block(context)
        let cgimage = CGBitmapContextCreateImage(context)
