From a recent issue of InStyle Weddings:
The Mom's Dress Code
N.Y.C. Bridal Atelier owner Mark Ingram, creator of Mark Ingram Atelier 2, for moms, explains how to avoid a MOB (mother-of-the-bride) scene
Tell them what you're wearing. The moms should take cues from you. "Let them know the shape, fabric and level of ornamentation of your dress so they can look for outfits that are in keeping with the tone," says Ingram.
Send your mom shopping first. "Traditionally, the mother of the bride buys her dress and then describes it to the mother of the groom," says Ingram. "Communication is key." Send his mother a photo, or tell her the color, style and designer so she can be careful not to outshine your mom—or dress as though she belongs at a different event.
Give them guidelines. It's well within your rights to steer both moms toward specific colors or styles (and away from others). How much influence you'll have depends on their personalities; but in a perfect world, they should follow these rules:
• Keep it in the (color) family. Choosing varying shades of your wedding palette makes things cohesive without looking too matchy-matchy.
• Nothing overly sexy. Even if Mom has been living at the gym, ask her to keep the hemline at the knee or below and the neckline on the conservative side.
• Their drama level should be below yours. If your dress has sleeves, theirs shouldn't be strapless; if you're wearing a sheath, they shouldn't be in ball gowns.
• No white. You'd be surprised at how many moms and mothers-in-law convince themselves that a "cream" dress is appropriate.