DVDs are component video not RGB and they can be in one of
3 frame rates. NTSC film (24/1001), PAL (25) and NTSC video (30/1001).

The first DVD player I bought, circa 2000 had a choice between multisystem
and PAL TV sets as a setup option. So have all the successive ones, except
a Sansui bought around 2001, which had a multisystem/PAL switch on the
back.

The Sansui one was also the only one that was zoned, at it could be
converted
by entering PI at the right time on the remote. The instructions were on
a piece of paper included in the box by the importer.

This raises a question that I've long wanted an answer to... If disks vary
according to frame rate -- how can there be a zone-free recording?