You can specify two different sets of link colors using CSS by targeting different states of the link. For example:
```css
a {
color: blue; /* Default link color */
}
a:hover {
color: red; /* Color when hovered */
}
```
You can also use classes to define different sets:
```css
.link-set-1 a {
color: green; /* First set color */
}
.link-set-2 a {
color: orange; /* Second set color */
}
```