Some consider blue "to be the color of pure water, whether liquid or solid." But, looking directly down into our waters from a boat, they are seen to be of very different colors. Walden is blue at one time and green at another, even from the same point of view. Lying between the earth and the heavens, it partakes of the color of both. — Walden—Walden
The focus of their reflected color is in the atmosphere far on this side. Every such tree becomes a nucleus of red, as it were, where, with the declining sun, that color grows and glows. It is partly borrowed fire, gathering strength from the sun on its way to your eye. — "Autumnal Tints"—"Autumnal Tints"
We have the silver and the golden birch. This is like a fair, flaxen-haired sister of the dark-complexioned black birch, with golden ringlets. How lustily it takes hold of the swampy soil, and braces itself! And here flows a dark cherry-wood or wine-colored brook over the iron-red sands in the somber swamp,—swampy wine. In an undress, this tree. Ah, time will come when these will be all gone. — Journal, 4 January 1853—Journal, 4 January 1853
We should read history as little critically as we consider the landscape, and be more interested by the atmospheric tints and various lights and shades which the intervening spaces create, than by its groundwork and composition. It is the morning now turned evening and seen in the west,—the same sun, but a new light and atmosphere. Its beauty is like the sunset; not a fresco painting on a wall, flat and bounded, but atmospheric and roving or free. — A Week on the Concord and Merrimack Rivers—A Week on the Concord and Merrimack Rivers