Aqua是Mac OS X 操作系统上的图形化界面的可视化主题，2000年首次推出。
Aqua is the graphical user interface (GUI) and visual theme of Apple‘sOS X operating system. It was originally based around the theme of water, with droplet-like components and a liberal use of reflection effects and translucency. Its goal is to “incorporate color, depth, translucence, and complex textures into a visually appealing interface” in OS X applications. At its introduction, Steve Jobs noted that “one of the design goals was when you saw it you wanted to lick it”.