Is it possible to set the selection colour of html form input text box?

Question

I want to be able to specify the highlight colour that appears around an input text box when a user selects it. By default (on a Mac) this always seems to be a light blue colour as per the screenshots below.

Does anyone know if this is possible and if so how?

Unselected:

Selected:

Answer 1

use

input:focus {
  border:/** your style definitions **/
  outline: /** **/
  box-shadow: /** **/
}