How to make a link text different color?

[Wonders]

How do you make links in posts/pms a different color from other text? Like for example:

I love http://www.chitnchat.net it is a great forum.

The link is blue and the text is grey, how do I change that so my links are blue on my site? Thanks!

[.m.]

theme's global.css consists code like below to show links in blue color

a:link {
    color: blue;
    text-decoration: none;
}

[Wonders]

theme's global.css consists code like below to show links in blue color

a:link {
    color: blue;
    text-decoration: none;
}

Where?

[.m.]

admin panel >> themes >> your forum's active theme >> global.css >> Edit Stylesheet: Advanced Mode

[Wonders]

admin panel >> themes >> your forum's active theme >> global.css >> Edit Stylesheet: Advanced Mode

How do I get it so it does it only for posts/pms? Right now when I do that it changes link text color for everywhere on the forum, wrecking the theme.

[.m.]

add below code at the end of global.css

.post_content a  {
        color: blue !important; 
        text-decoration: none!important;
       }

[Wonders]

add below code at the end of global.css

.post_content a  {
        color: blue !important; 
        text-decoration: none!important;
       }

Do I still add the other code or only this one?

[.m.]

^ only the above (post #6)