The red wavelengths of light are the longer wavelengths and the violet wavelengths of light are the shorter wavelengths. Between red and violet, there is a continuous range or spectrum of wavelengths.
The USPS also includes that a large postcard is 49 cents to mail. The maximum size for this postcard is 11 1/2 inches long, 6 1/8 inches high and 1/4 inch thick. This is the same rate to mail a First Class 1 ounce letter domestically. The rates for postage increased as of January 2014.
Postcard mailings and the 2015 postage increase. You can qualify for discounted postcard postage at the Presorted First Class rates ranging from 24 - 30 cents per postcard (exact rates depend on the addresses contained in the list) when your list contains 500 or more addresses.