The Swamp Gas colour was released on June 21, 2011. Users can change the colour of their Neopets to Swamp Gas by using a Swamp Gas Paint Brush item at the Rainbow Pool. The Lab Ray has a random chance of turning the colour of a user's Neopet to Swamp Gas. Users also have the choice of changing their Neopet's colour to Swamp Gas when they complete a Fountain Faerie Quest.
The following Neopets are currently available in the Swamp Gas colour:
- Rainbow Pool: Swamp Gas