This painting was an exercise in color from a sketch I made at the Vanderbilt estate along the banks of the Hudson in Hyde Park New York. I tried to keep the pitch down using fully saturated color so that the sun would have sufficient contrast- much the way one would pitch the sky in a snow scene lower in value in order to make the snow appear bright. The foreground trees are silhouetted in dark values to establish the vignette and range of tone. I alternated cool and warm reds in the clouds to distinquish between the sky vortex (light filled air) and the cooler cloud shapes. In the sky zenith(top of the vault), I substituted a thalo green-viridian mixture without any blue to push the color contrasts between the red and greens. I suspect this kind of color layering and emphasis is what Rothko was exploring in his "landscapes".