When you are having a portrait taken it is recommended that you carefully choose your clothing as you want the focus to be on the faces and not what you wear. Typically simple clothing in solid colors will not be a distraction. When you look at this portrait in a few years, you want to see the faces, not the fashions of the time.
In group photos, your clothing should make you look like a unit. You probably don’t want to match colors and patterns in clothing but coordinating the colors makes you look like you belong together.