Updated the drawRect code to quench Scott’s never-ending thirst for nitpicking the work that others so kindly take the time to contribute to his cause.

… err…. I mean:

· Added a new color-fill to simulate Apple’s apparent darkening of the alert. This seems to come from outside the domain of the background color and radial gradient attributes.
· Tweaked that layer’s transparency to better-match Apple’s aesthetic rather than their exact color values.
· Introduced an “overlay” blend mode to bring the effect together as closely as possible. None of them matched 100%, but this one was the closest to identical replication.