in Thoreau’s Journal:

The woods generally may now be said to be fairly beginning to turn (this with the first noticeable frost). The red maples, especially at a distance, begin to light their fires, some turning yellow, and within the woods many oak, e. g. scarlet and black and chestnut, and other leaves begin to show their colors. Those leaves of the young white oaks which have changed dull-salmon, crimson, scarlet (many incline to crimson) are mostly within the tree and partially concealed by the green leaves. They are handsomest looking up from below, the light through them.