says red32uf, yellow 32uf, green 32uf, can negative
ahh, it's one of the ancient types. ok, strap yourself in... typically on a multi-section cap you have a shared ground tab plus two or more +'ve connections.
in the type you describe, the actual body of the can is your ground connection - is it a twist-lock type with the body fixed to the chassis directly? anyway, the other three sections (red, yellow, green) are all +'ve connections.
those three-section caps are much harder to find these days - I had to replace one in a Selmer T&B one time and ended up with a dual-section can cap and a single axial cap wired to some tagstrip.
it's a bit better now though as I'm sure JJ and maybe even F&T make a three-section can cap.
(ok, back now), AES stock the JJ four-section cap, but it's a 40uF, 20uF, 20uF, 20uF cap...
http://www.tubesandmore.com/scripts/foxweb.dll/moreinfo@d:/dfs/elevclients/cemirror/ELEVATOR.FXP?item=C-EC40-20X3-500 Wire it up with two of the sections in parallel so you get 40/40/20. the slightly lower filtering on the 20uF stage will make a negligable difference, but if it bothers you just add a 20uF axial cap across that section of the can cap and have 40/40/40 - perfect!
actually, looking again, they stock a 30/30/30uF can cap which is perfect, or you could get the 40/40/40uF one if you want slightly more filtering... CAPACITOR, ELECTROLYTIC, 30/30/30 µF @ 525 VDC... part# C-EC30X3-525 (30uF x3 @ 525v)