Hungry little devils, aren't they?
  -- Dusty (to a Cobra agent, who is pinned down in a pool filled with piranhas)
Home Toy Commercial Animation Cobra Swampfire & Dreadnok Thunder Machine (1986)

There was perhaps a miscommunication between the animators and the toy designers. The Dreadnok Swampfire was supposed to change colors, not Zartan's sister and brother, Zarana and Zandar, and even the song notes that the Swampfire was to change colors in sunlight. But as Breaker said in the miniseries G.I.Joe: A Real American Hero: "Nobody's perfect."
The contrast between the murky waters and mist-shrouded trees in the background versus bright lasers and quickly moving allows the Joes to appear even more vibrant in the eyes of the viewer.
Because the animators cut to a shot of the Dreadnok Thundermachine, which is carrying Ripper, Buzzer and Torch, barreling towards the camera, the audience is drawn into the action.

Jan 25: G.I.Joe Examined on Podcasts
Jan 25: Buzz Dixon Interview
Jan 25: Paulsen Annie Nomination & Dini on Batman Comic
Jan 12: Sgt. Slaughter Signing in Atlanta
Jan 11: G.I.Joe to Return on G4
Dec 30: Paramount Movie Reviewer Plugs JoeGuide.com
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