Are ants purple or green

Yes, they do - though not all colors in one ant.

• Green. Green Tree ants are green. The Green-headed ant has a metallic green sheen on it head.
• Yellow. There's the Citronella ant and the Yellow Meadow ant and the Yellow Crazy ant.
• Purple. Large Purple Meat Ants. Depending upon local or lighting, they might have a purplish hue.