css disable underline on hover code example

Example 1: how to change hyperlink color in css

a {
  background-color: red;
  color: white;
  padding: 1em 1.5em;
  text-decoration: none;
  text-transform: uppercase;
}

Example 2: how to put a h1 tag with underline ::after

h1:after {
   background: none repeat scroll 0 0 #HEXCOLOR;
   bottom: -10px;
   content: "";
   display: block;
   height: 10px;
   position: relative;
   width: 100px;
}