Although coin coloring is not endorsed by the U.S. Mint, businesses have the right to colorize the coin, as long as they adhere to certain guidelines. One is that the coin design must not be copyrighted by the U.S. Mint. Another is that the colorized coins must not be turned into advertising vehicles.
In the summer of 2007, 20th Century Fox and the Franklin Mint colorized 40,000 quarters with the image of the Marvel Comic hero, the Silver Surfer, on the flip side to Mr. Washington. The coins were designed to promote the summer blockbuster, "Fantastic Four: Rise of the Silver Surfer."
As soon as the U.S. Mint got wind of this promotion, it issued a news release stating that it neither approved or endorsed the use of the 2005 California Statehood quarter as a marketing device, and that the two companies had broken the law. 20th Century Fox had planned to release 800 of the Silver Surfer coins in each state over Memorial Day weekend. Fans who received the coins could enter special contests online and attend special viewings of the film.
This just goes to show the importance of ensuring that a colorized coin meets the standards and guidelines issued by the U.S. Mint. However, as a collector, you can be sure that if you’re lucky enough to get a colorized coin that is banned or pulled out of circulation, you have a gem!