Color Monte is a good trick, and I like it, but it's a bit easy to figure out if someone sees it several times (I watched the video on Penguin Magic a few times and eventually caught on, then just repeated it with normal cards). A good trick I find that's difficult to spot after several times is the Raven/Bat, but once again, those with a creative imagination might be able to solve it.
As a rule of thumb for magicians, only perform tricks once. If you perform a trick many times, people will be able to see how it's done (especially with tricks that rely on misdirection).
If someone asks you to perform the trick again, it's usually best to either perform a different trick (could say you performed the original wrong or something, heh), use a line as to why you can't do it again (the only one I've heard recommended was "Once is magic, twice is entertainment." but I try to use something along the lines of the trick. Something like "I can't make it dissapear twice, it's already gone!" Or you could just use the straightforward "If I perform tricks many times, people might start to figure it out!" but that kind of takes away from the idea that what you're doing is magic.), or just run away to avoid them.
Oh, and I'd recommend the book Royal Road to Card Magic (rrtcm) by Jean Hugard and Fred Braue. You can order it online from many sites, or find it in a bookstore/library. If you can't find it and don't want to wait for it to ship to your house, here's a website where you can order the ebook version of it (for dirt cheap too!):
http://www.lybrary.com/royal-road-card-magic-p-35.html
After getting through that, check out Expert Card Technique by the same authors. There's a link to the ebook version in the site above.