So you own one too. Welcome to the club.
Mine came with a print out of this webpage that tells the interesting history of how these decks came to have non-EIAJ-standard color.
http://www.labguysworld.com/Sony_AV-5000A.htm
Mine still works (I had to record a color tape on it to watch it in color) but belt slippage and the tapes getting sticky makes picture quality and sync vary. Wish I had the lid for mine...
I've got 3 EIAJ decks the Sony AV5000A , another Sony (model 36something)that's EIAJ standard color, and a monochrome Concord.