Depth&Volume is a Control Panel that lets you change the main screen
depth (i.e. the number of colors displayed) or the speaker's volume on
the fly with a keystroke. Depth&Volume is very small (it uses about 2K
of system memory) and very easy to use ... once you get into the habit
of remembering the keyboard shortcuts.

The following keys are used to change the display's colour depth
(where "#" is the modifier key combination chosen in the Control
Panel):

 * #1 = Change to 1 bit (black and white)
 * #2 = Change to 2 bit (4 colors or greys)
 * #3 = Change to 4 bit (16 colors or greys)
 * #4 = Change to 8 bit (256 colors or greys)
 * #5 = Change to 16 bit (thousands of colors)
 * #6 = Change to 32 bit (millions of colors)
 * #7 = Switch to greyscale mode
 * #8 = Switch to color mode

The following keys are used to set the speaker volume (where "*" is
the modifier key combination chosen in the Control Panel):

 * *0 = Silent (menu bar flash)
 * *1 = Volume 1 (quietest)
 * *2 = Volume 2 (quieter)
 * *3 = Volume 3 (quiet)
 * *4 = Volume 4 (medium)
 * *5 = Volume 5 (loud)
 * *6 = Volume 6 (louder)
 * *7 = Volume 7 (loudest)

First download is v1.0 from 1993. It is on a Disk Copy 4 disk image
(1.44MB) inside a StuffIt 3.5 archive.

Second download v1.0.1 freeware since 1996

Compatibility
Architecture: 68k

Obviously the computer's capabilities will limit which Depth modes
will work - you can't change to "Milllions" of colours on a Mac Plus
for example.