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.
4 1/4 x 6 x .016 thick. To send a postcard to an international destination the rate is $1.20, up from $1.15 as of the same May `015 date. As of Jan `014 large postcards rose 3 cents to $0.49, up from $0.46 to mail. These have maximum dimensions of 11 1/2 x 6 1/8 and can measure up to 1/4 thick.