The Solaris X server supports devices that can display windows of more than one pixel depth simultaneously. These devices are called multi-depth devices. Since most of these devices are implemented with separate groups of bit planes for each depth, the term multiple plane group (MPG) device is often used for these devices.
For each depth, there might be one or more visuals exported. For most MPG devices, windows can be created using any of the exported visuals. For applications that prefer a TrueColor visual, the developer should determine whether the TrueColor visual is available, since it may be available even if PseudoColor is the default visual.