Graying out texts with/without lines with LaTeX?

Question

This is a screen capture from Pragmatic Bookshelf.

How to make this boxed text with LaTeX? It has it\'s own heading with underline, and uses color.

And

Answer 1

You should use the color package.

For example,

\colorbox{red}{Black text on red background}

creates a black text, with a red background. A good description of the color capabilities can be seen here, and an extended example here.