Show the structure of color style?

Example

<style>
a:link {
    color: green;
    background-color: transparent;
    text-decoration: none;}

a:visited {
    color: pink;
    background-color: transparent;
    text-decoration: none;}
a:hover {
    color: red;
    background-color: transparent;
    text-decoration: underline;}

a:active {
    color: yellow;
    background-color: transparent;
    text-decoration: underline;}
</style>