Rainbow extends ruby String class adding methods to wrap the string
with ANSI escape codes.

Rainbow adds following methods to String class:

 * foreground(color) (with color and colour aliases)
 * background(color)
 * reset
 * bright
 * italic (not well supported by terminal emulators).
 * underline
 * blink
 * inverse
 * hide.

WWW: https://github.com/sickill/rainbow