[HarryT]

Yes - you do it with CSS style for the "a" element. You need something like this:

a {
  text-decoration: none;
}

a:link {
  color: #265301;
}

a:visited {
  color: #437A16;
}

The first of these sets the general style for links (removing the underline). The second sets the colour for links you haven't yet clicked on. The third sets the colour of links you have clicked on. Adapt as required. You need to have the classes in this order - each builds on the one before it.