Robert Francis (August 12, 1901 - July 13, 1987 / Pennsylvania / United States)

Winter uses all the blues there are.
One shade of blue for water, one for ice,
Another blue for shadows over snow.
The clear or cloudy sky uses blue twice-
Both different blues. And hills row after row
Are colored blue according to how far.
You know the bluejay's double-blur device
Shows best when there are no green leaves to show.
And Sirius is a winterbluegreen star.