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.
Under a filing with the Postal Regulatory Commission, letters to international destinations would rise from $1.15 to $1.20. Postcards would rise from 34 cents to 35 cents. The increases being proposed would become effective April 26, if the requests are granted. On first-class mail, every ounce over 1 ounce would cost an additional 22 cents, up from 21 cents. And letters to all international destinations would go from $1.15 to $1.20.