Aqua controls in OS X Yosemite. It was originally based around the theme of water, with droplet-like components and a liberal use of reflection effects and translucency. Its os x human interface guidelines pdf is to “incorporate color, depth, translucence, and complex textures into a visually appealing interface” in macOS applications. At its introduction, Steve Jobs noted that “one of the design goals was when you saw it you wanted to lick it”.
The appearance of Aqua has changed frequently over the years, most recently with the release of OS X Yosemite in 2014 which introduced a flatter look and did away with the gel-like controls and metal-like components. The first version of the Aqua GUI, from Mac OS X Public Beta.
It differs vastly from the GUI of Mac OS 9 with glass-like elements and a Dock, among other things, although the Apple Menu reverted to its traditional position on the left-hand side of the menu bar for the final release of OS X 10. The Panther version of the Aqua GUI shows several changes, most notably brushed metal. The Aqua GUI in Mac OS X Leopard. Among the changes were a gradient window style and a new Dock and menu bar.
2 “Jaguar” brought flatter interface elements, such as new buttons and drop-down menus, as well as reducing the transparency to tone down the pinstripes in windows and menus. These trends continued in subsequent Mac OS X releases. In Mac OS X Panther, brushed metal was brought to the Finder.
New buttons were made to appear sunken into their surroundings, following a general trend of more flattened interface elements in the operating system. Tab buttons were centered on the top border of the tab area.