Its better to wear a plain color tie because.. Looks better. Makes you look more work savvy. People will notice you more.. On the other hand.. Too much colour will make you look gay. People will say you are looking for attention. And Persons will not take you seriously.
Depends are you getting married? Or going to be on television? Ties aren't even really in right now. If you have to wear a tie. Get a subtle design or pattern. If you want a multi colored tie. Go with a J. Garcia.