Java Swing Components - why deprecated HTML markup?

I'm learning Java from a webdev background. I've been using some HTML inside Swing components, but a little part of me dies every time I see or write

<p color=red>Two<br>Lines</p>

So I can sleep at night, what's the reason for this po开发者_Go百科or, deprecated markup? And, if I use XHTML and inline styling, is my program at risk of being unsupported?

Swing supports only limited CSS without a third-party package; that's just the way it is :)