Hi Dave, the colours for the SB 320 Demon, B&S 3.5HP and is model number 320039, is the same colour for all the 1978 model line-up which is the same hammertone olive green colour that, unfortunately, the formula no longer exists.
However, quite a few members have been using White Knight "Alpine Green" hammertone finish which is lighter in colour, but is available from Bunnings etc. in a spray can and apparently works well....(see some of the latest SB45 restorations.) Here is the 320, top right in the drawing.
