Hi Alen Thomas. Welcome to the forums.
What you have will work fine, as long as the path to your CSS file is correct. What you have at the moment:
<link <font color='"#FF0000"'>href="style1.css"</font> rel="stylesheet" type="text/css"/>
is telling the browser to look for the style1.css file in the same folder as the page itself. But if your CSS file is stored somewhere else, the path needs to be different. E.g. if the CSS file is in a folder called /styles/ in the root folder, the link would look something like this:
<link <font color='"#FF0000"'>href="styles/style1.css"</font> rel="stylesheet" type="text/css"/>
So the question is, where is the CSS file in relation to your page?