The same clothing rule applies to pageants as applies to a friend's wedding--dress nice enough to show respect for the star of the show, but not so glamorous that you draw exorbitant amounts of attention. The simple classification for proper pageant wear, at a small or regional contest, is semi-formal. At a national competition, dress should be formal. Many pageants will specify their expectations of clothing for spectators. The expected dress code will also be partially determined by the time of day. An evening pageant will be more formal than a daytime pageant.

Semi-Formal Dress is classified as a step below formal and a step above business attire. There is a fine line between semi-formal and cocktail dress. Semi-formal is characterized by a more modest style than cocktail wear. The type of pageant requiring semi-formal wear is a local pageant or a daytime regional pageant. According to Bella Online, semi-formal wear is much more formal than cocktail wear. For men, writes Lisa Plancich, semi-formal wear should include a jacket, pants, vest and tie. Women should wear dressy heels, strappy sandals, or flats. The colors of the purse and shoes should coordinate with a long dress. Children should dress in a similar style to the adult of their gender. Of course, it is more difficult to convince a little boy to wear a vest and tie. When taking children to a semi-formal event, do not force them into uncomfortable clothes if the child refuses, or the pageant will be more unpleasant for all involved. It is acceptable for a child to wear nice pants and a dress shirt, as long as they look polished and groomed.

Formal dress between day and night is primarily distinguished by colors. Day time formal wear should incorporate cool colors, like blue, green, and violet. You may also wear pinks and pastels. All jewelry and accessories should match the color scheme of your outfit. For men, a suit is acceptable for formal day wear. This should be a five-piece suit, with a vest, shirt, tie, trousers, and shoes. According to The Etiquette and Dress Experts, shoes should be well-polished, and socks should match the shoes. For women, another distinction between day and night formal wear is the length of dress. At a day pageant, women should wear knee-length dresses. The Dress and Etiquette experts say that jewelry should be added for glitz and shimmer, and strappy shoes are appropriate.

Formal dress for an evening event should be very similar to formal day dress, except that colors should be warmer. This dress code is necessary at large, national pageants. A good color palette for evening wear is warm, dark colors. Red is a beautiful colorful for evening wear, along with black. Dark greens and blues may also be worn, or gold and silver. According to Fashion for Real Women, flowing or beaded fabrics are appropriate. Women should wear floor-length dresses and heels. A shawl may also be worn for additional warmth and style.