For the most part, that looks like it's after the pinstripes were toned down, but before the brushed metal fad took hold. So there's plenty of use of color and

For the most part, that looks like it's after the pinstripes were toned down, but before the brushed metal fad took hold. So there's plenty of use of color and enough depth to make it easy to distinguish between UI elements. But as noted by others, there are some legacy holdovers on display, too. It's probably one of the most "timeless" looks ever used by OS X.