Idk...maybe it was meant to be a reptile tank. Just a thought, but is there maybe a clear green-colored plastic film/sheet on the glass to keep it from scratching while at the store. You may be able to peel it off.
ok figured it out it's because the glass is so thick about a inch thick looked at my 55 and the glass looked green on the corners i feel like a dummy sorry for wasting your time
The majority of glass tanks have a green tint to them because of the iron content.You will not notice it once it is filled with water.If you want a clear glass with low iron content then get a tank made of Starphire,they are pricey though.