See-through computer mice used to be created as prototypes during the development of the devices, but the cases of the production models were opaque plastic, most often a shade of beige. Photos of a clear Hawley mouse [external link] and a three-button Apple prototype [external link] can be found on the Web and several transparent Lisa mice reside in at least one private collection. When a few manufacturers marketed clear mice, at last curious users could see the mouse workings without taking the mouse apart and risking getting it back together improperly and/or, gasp, voiding their warranty.
Transparent mouses seem to have inspired the transluscent variety in later years. Here are a few in the album.