Appearance Manager

Previously, controls made direct QuickDraw calls to draw user interface elements such as buttons, scrollbars, window title bars, etc.

This extra level of indirection allows the system to support the concept of switchable "themes", since client code simply requests the image of an interface element (a button or scroll bar, for example) and draws its appearance.

An updated and more powerful version of the Appearance Manager was used for Carbon applications in Mac OS X even after Apple made the transition to Aqua.

The default look and feel of the Appearance Manager in Mac OS 8 and 9 is Platinum design language, which was intended to be the primary GUI for Copland.

Customizable palettes ('clut' resources) are used for progress bars, scroll thumbs, slider tabs and menu selections in Apple Platinum and this unique option is not available to real themes.

Hi-Tech is based on a shades-of-black color scheme that made the interface look like a contemporary piece of audio-visual equipment.

[1] One retrospective review by a long-time Mac user described the themes as being a mistake and waste of engineering resources, saying the "Hi-Tech" theme "looked like a typical dark over-decorated techno skin that became popular for Linux desktops" and that "Gizmo" looked "awful...the Finder in a clown suit".

[3] By default, a font called Charcoal is used to replace the similar Chicago typeface that was used in earlier versions of the Mac OS.

Kaleidoscope, written by Arlo Rose and Greg Landweber, applied "schemes" to the GUI before Apple released an update to the Appearance Control Panel with Mac OS 8.5 which provides similar functionality using "themes".

Steve Jobs returned to Apple just before the release of Mac OS 8.5, and he decided to officially drop support for themes because he wanted to preserve a consistent user interface.