Related Clues:

• Thermostat feature
• Push-button alternative
• Tune in
• Lock feature
• Use an old-fashioned phone
• Old postcard tone
• Hue in old photographs
• Photo-editing effect
• Pigment from cuttlefish
• Place a call
• Push-button precursor
• Cuttlefish fluid used in art
• Pigment used in drawing
• Thing a host might warn you not to touch, after 'that'
• Panel reading