| http://www.w3.org/ns/prov#value | - According to the present invention, at least portions of the pattern 10 of FIG. 1 are coated such as by overprinting with photochromic materials which, when exposed to ambient light of sufficient intensity such as direct sunlight, changes color to produce a different color which is intended to be representative of the coloring effect produced in nature and which occurs during a substantial change
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