The Greens are the partisans of the development of an open-air biosphere on Mars, and are in favor of terraforming. They are in opposition with the Reds. Sax Russell is commonly acknowledged to have initiated the Green movement, thanks in no small part to his public debates with Ann Clayborne, the original Red. Ironically, they represent a progressive force of change, but they bear a name traditionally linked to movements desiring conservation of wildlife and the environment (on Earth).

The life-celebrating Areophany promoted Green ideas and had a great impact on the Martian underground. Following the progressive changes brought on Mars's surface, many movements joined by Martian natives, such as Free Mars, were Green.

After the Second Martian Revolution and in a spirit of reconciliation, many concessions were made to the Reds, such as the leadership of the Global Environmental Court. Martian customs changed from mainly Green to something closer to the concept of ecopoesis. As terraforming reached completion, the concept of Browns emerged.

Famous Greens

• Hiroko Ai
• John Boone
• Nirgal
• Sax Russell
• Vlad Taneev
• Harry Whitebook