Being the mother of the groom can be a tricky spot. You want to be involved in your son's wedding, but want to avoid stepping on anyone's toes. There are a few etiquette rules to follow when picking out your attire, but communication with the bride and her mother are key.
Tradition states that you allow the mother of the bride to pick her outfit first. Then you pick yours to complement hers.
Ideally you want to pick a colour that compliments both the attire of the mother of the bride and the bridesmaids, but avoid matching exactly, unless the bride has requested this.
Colours to Avoid
Above all you should avoid anything in the white or ivory colour family, as this may insult the bride. You should also avoid black because it is associated with mourning, and red due to its flashiness.
Although traditionally both mothers wear dresses, trousers are an acceptable alternative so long as they are not too casual.
When debating on exactly what style of dress to wear, in addition to the mother of the bride's dress, keep in mind the type of wedding being held. You would dress much more casually for an outdoor afternoon wedding with a cake and champagne reception than you would an evening wedding with a sit-down dinner reception.