As some of the earlier tips have said, it's much quicker to manipulate strings within either SQL Server or compiled components. However, if you are generating HTML from one of these sources, you would have to embed colors, fonts, and such in the HTML you're generating. If you change the look of your page, you'll have to go back to your compiled code or your stored procedures and change all the code.
An alternative I personally use is to generate style sheet tags from the compiled components and stored procedures. This allows me to change the colors, fonts, and other attributes outside of the code. In addition, I can use the same code for multiple sites since the style sheet can be redefined for each web site I used it with.