I have a bunch of tanks in my fishroom with various shades of green backgrounds. The glass and water make them look one to two shades lighter in color and more blue FYI. Dark green looks a few shades lighter when water and lights on in tank. I have also painted quite a few tanks various shades of tan and brown. They look pretty good. Any latex paint left over from house projects work well. I clean the glass first with alcohol and paint on with a brush, takes a few coats.








