Don’t wear white because it competes with the bride. There are plenty of other colors available.
Don’t wear black or sequins during the daytime.
Don’t worry about wearing the same colors as the bridesmaids or mothers. You can’t possibly coordinate with everyone in the wedding party.
Do wear something feminine and appropriate, out of respect for your hosts. Clubwear, overtly sexy clothing (strapless, see-through, etc) doesn’t belong at a wedding. If you have to ask if it’s appropriate, it probably isn’t.
Don’t wear opera-length gloves (to top of arm) with anything but sleeveless or strapless gowns.
Do take off gloves to eat or drink.
Do use good judgment if the invitation doesn’t specify the formality of the event. A pastel suit or soft floral dress for daytime or a little black dress for evening (after 6 p.m.) will take you almost anywhere.