John Ruskin,
The Storm-Cloud of the Nineteenth Century
“ These with full blue breathed between them at the zenith, and green blue nearer the horizon, form the scales and chords of color possible to the morning and evening sky in pure and fine weather; the keynote of the opposition being vermilion against green blue, both of equal tone, and at such a height and acme of brilliancy that you cannot see the line where their edges pass into each other.No colors that can be fixed in earth can ever represent to you the luster of these cloudy ones. ”
