Not on a Mac it doesn’t. “.bmp” format is not used on a Mac for anything, and the contents of the clipboard are never dithered to 256 colors. Copy a 32-bit image and past it elsewhere and you get a 32-bit image where you paste. The Mac clipboard uses: (MacOS 9, 8, 7, etc): PICT format or (MacOS X): PDF format as its/their native format, and it’s all a 32 bit world. Come to think of it, in this day and age I’d be astonished if Windows really dithers clipboard copies to 256 color bitmaps. That’s so windows-3.1ish. I’m not a Windows geek and will accept correction from Windows users, but it seems sufficiently unlikely that I have to ask: cite?
Consider yourself astonished, then. On my Win 98, with Word 2000, copying a JPG image from a DOC file to the clipboard, then pasting into a new 24-bit color file in Corel PhotoPaint 7 creates a “palleted” 256-color file, which few other application programs do. It looks fugly. Cite? I just tried it again, and it did it again. I cannot vouch for other operating systems or Word versions.