This footage was provided by Channel 9 management to me, and with their permission has been allowed to be uploaded
It is the never-before-broadcast colour transmission of the 1973 Grand Final, one year before colour TV transmissions were trialled. (From 19 October 1974, Australian Broadcasting Control Board permitted stations four weeks of live color broadcasts for no more than four hours per week and no more than two hours per day).
Colour TV was officially introduced on 1 March 1975.
The director of the time John Crilly confirmed to me that although filmed in colour, the Grand Final highlights were still broadcast in black and white on Grand Final night on Channel 9, as no one had colour television, and the transmission stations up on Mt Dandenong had yet to be upgraded to colour.
The only colour transmission was on the day, into Crilly's director van at the MCG. Ch9 were testing what the colour transmission looked like before the introduction of color TV the next year.
Therefore, this Youtube upload is the first public transmission of the colour filming of the entire game.