Tonto spent years working on perfecting the art of mixing colors. He drew his inspiration from the journals of Vincent Van Gogh, who wrote, "It is impossible to say, for instance, how many green-grays there are; there is an endless variety. But the whole chemistry of colors is not more complicated than those few simple rules. And having a clear notion of this is worth more than 70 different colors of paint -- because with those three principal colors and black and white, one can make more than 70 tones and varieties. The colorist is the person who knows at once how to analyze a color, when it sees it in nature, and can say, for instance: that green-grey is yellow with black and blue, etc. In other words, someone who knows how to find the grays of nature on their palette.”

Finally, he came up with the perfect combination of pigments for his signature color of paint. Now, the walls of every hospital in the world are covered with the “Fielding Shade” of green.