(MacDraw Pro 1.0) In the Installer, one Installation option is called Color Support Software. This option installs 32-Bit QuickDraw and LaserWriter 6.0.2 files.
If the Installer is launched with System 6, Color Support Software is listed to be installed when performing an Easy Install. However, if the Installer is launched with System 7, Color Support Software will NOT be listed to be installed using the Easy Install button. (This is appropriate, since these files are not required with System 7.)
If Color Support Software is selected using the Custom Install feature while running System 7, the Installer will install 32-Bit QuickDraw and the LaserWriter 6.0.2 files into the System Folder. These files are installed even though they are not appropriate for System 7. These files will not cause any problems if left there, but they are unnecessary additions to the System Folder. (The LaserWriter files are installed into the System Folder, not the Extensions folder.)
When using the Custom Install feature, the Installer installs all the files related to the chosen installation options, whether those files are appropriate or not. The Installer only checks system and CPU types (to modify what it will install) for use with Easy Install.