&lt;font color="yellow"></font>Hi there.&lt;/font></font>

gives

<font color=yellow>Hi there.</font>

You can also use hexadecimal color codes like

&lt;font color=#A76593></font>I picked a random code.&lt;/font></font>

<font color=#A76593>I picked a random code.</font>

Look at the site Shoyku gave, it's very handy. Please don't misuse HTML here at the MB. Yeah, it's neat to play with it, but it's painful to force everyone to look at it.