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.
As of January 22, 2017 the price for sending a post card remains at $0.34. The same amount effective April 10, 2016 when the rate for sending dropped to $0.34, from $0.35. The January `017 date is the same as for other rate announcements, including that for certain postage stamp prices.