What is coloring material?

Famous quotes containing the word material:

    To one who habitually endeavors to contemplate the true state of things, the political state can hardly be said to have any existence whatever. It is unreal, incredible, and insignificant to him, and for him to endeavor to extract the truth from such lean material is like making sugar from linen rags, when sugar-cane may be had.
    Henry David Thoreau (1817–1862)