There seems to be a lot of copper and iron around Chicago. The metal work is so colorful, with the iron colored from golden ocher to almost aubergine and the copper taking on lovely green and turquoise patinas with some soft mauve tones as well. Even the concrete sidewalks become stained with color. I love these grids.
I was surprised when I stumbled upon this plaque on the wall of a building about 4 blocks down the street from where we live, it's funny I hadn't noticed it until recently.
I think the tree grates they put down a couple years ago were intended to rust because they were pretty orange from the time they went in and they just seem to get more colorful all the time.
And when you push the saturation up in Photoshop you get all kinds of pretty colors.