This fall, Manchester's trees aren't just turning orange, red, and yellow - they're also turning blue.
"The Blue Trees" installations started fifteen years ago, when Dimopoulos moved at the age of 45 from New Zealand to Melbourne, Australia. Dimopoulos' native city had been so windy it was virtually treeless.
But Melboune was an urban forest.
Standing at the Currier Museum in a Carhartt jacket and blue paint smeared on his cheeks and hands, Dimopolous smiles remembering how he became a tree lover.
"I remember watching the leaves fall in the autumn," he says. "I thought wow - it's just so stunning, so beautiful."
But then he started reading about all the places where trees were disappearing - in clearcuts in Southeast Asia and the Amazon.
"It’s always just a postscript in a newspaper saying forest disappears so we thought: how do we get cities like Melbourne, like New York, like Manchester, who have a lot of trees to be aware that though they have a lot of trees, the relatives of their trees are being destroyed?"
Dimopolous’ answer: get people's attention by paint urban trees blue.
He and his wife spent two years experimenting to find the right color; they finally settled on a chalk-based, biologically safe pigment that disappears off the trunks after about six months.
The blue is hard to describe. One volunteer says it looks like the brilliant blue of a peacock feather. Another suggests a mix between royal and cobalt. Dimopolous says it doesn't have a name - he just calls it "electric."
"Blue is very much - it has a religious space to it," he says. "And in fact the one thing that gives you oxygen is the tree; it’s almost as close to God as we can be when you’re in the forest because the tree brings oxygen and gives you life."
"The Blue Trees" is sponsored by the Currier Museum of Art in Manchester.