textarea by default supports HTML, therefore you could put in tags inside the textarea and the text will be formatted...
What you could do is to format the text afterward after you submitted your textarea vars via POST or GET.
$formattedText = "<p>". $_POST["textAreaStuff"] . "</p>";
And using css, you could format it nicely.
<style>
p {
background-color: #999999;
color: #000000;
font-family: Verdana;
font-size: x-small;
}
</style>
However if you want to format the textarea realtime, then you should use CSS and format the textarea element.
<style>
textarea {
background-color: #999999;
color: #000000;
font-family: Verdana;
font-size: x-small;
}
</style>
Preferably assign a class to avoid confusion.
<textarea class="nicer">inside text</textarea>
<style>
textarea .nicer{
background-color: #999999;
color: #000000;
font-family: Verdana;
font-size: x-small;
}
</style>
Whatever suits you best.
Good luck!