Container colour coding works only if staff can identify the right container quickly during a busy shift. Do not treat colour alone as a safety or hygiene control.
Make the key visible
Define a colour, short label and, where useful, symbol for each use. Post the key where containers are stored; take raw/cooked or clean/dirty distinctions from the operation's existing procedure.
Trial the real task
Ask staff from different shifts to direct sample products or waste to the correct container. Record correct choices, mis-sorts and hesitation; check faded, dirty or poorly lit containers separately.
If the trial finds errors, enlarge the text or symbol, make colours easier to distinguish, or separate container shapes. Train the scheme with the current procedure and observe again after changes.