Can I copyright or trademark a unique concept?

Your question is a little vague. You can't really protect just a "concept." We need more flesh on that bone. You protect inventions with patents, source-identifiers with trademarks, and tangible expressions of ideas with copyrights. Which of those categories would your concept fall into?

I agree with my colleague.

The USPTO protects trademarks and patents. Exactly what kind of unique concept your query refers to is a mystery. If it's a TV show, you need to develop this concept so you can register it with the Writer's Guild and and the U.S. Copyright Office and then pitch it to TV producers.

This is an incredibly open ended question that needs more followup. Your initial question is whether you can copyright or trademark a unique concept. What this is basically asking is whether you can copyright or trademark an idea. The short answer is now. But your followup comment sheds some light on the root of the question. Based on the limited information you've provided, it sounds like you are interested in the ways you can obtain legal protection for something like a television show. Television shows can be protected by copyright, but only to the extent that there is a unique expression. Therefore, the concept (or idea) behind "Who want's to be a millionaire?" cannot be copyrighted, but some of the elements of the show might be. Television shows may also receive trademark protection. If a mark (such as the show's title) becomes identified by the public as a source for a particular good or service (i.e., the TV show), then the mark might receive trademark protection. The logos for television shows are another way a TV show might be protected. These can receive both copyright and trademark protection. There are other ways to protect it as well. There are common law rights protecting pitches to producers under California law. I believe there have been changes in this recently, so talk with a California lawyer (or a lawyer in your jurisdiction) to find out what rights you might have. Another way to protect a pitch is to require the folks listening to it to sign an agreement that essentially says they won't steal the idea and use it themselves. Based on the open nature of your question, however, what you really need to do is sit down with an entertainment law specialist and talk about your ideas, goals, and how to reach them while protecting yourself legally. Good luck with it.