Green’s Dictionary of Slang

1. venereal discharges, pus.

1732

Progress of a Rake 50: She’d have no nasty, pocky Fellows, / Dribbling her Sheets with Greens and Yellows.

2. (Aus. prison) prison uniform; thus used as a generic for prisoner activities.

1990

Tupper & Wortley Aus. Prison Sl. Gloss. 🌐 Greens. Prison clothing issue (NSW). Also derived adjective used to describe prisoner activities eg green talk, which is prisoner talk. Opposite to ‘blue’.