Background help, what color and is "seaview" background sealant worth the money?

I've never put a background on any of my tanks before, but I wanna try it. I am wondering what color would make the fish look the most colorful? I'm thinking this one a href="http://i.ebayimg.com/11/!BRkfR)Q!Wk~$(KGrHgoH-CIEjlLl0nU1BJ-ug,6pn!~~_12.JPG" rel="nofollow"http://i.ebayimg.com/11/!BRkfR)Q!Wk~$(KG…/a also, what is the best way to attach it? That seaview stuff looks pretty cool if it's actually as easy as they make it seam lol Thanks for any advice on this :-)