Usually brides send the invitations 3 months before the wedding. If it’s out of town guests, four months is better. Sending the invitations out early gives time for your guests to book flights and arrange a hotel. If the wedding is during the summer or beginning of fall, send your invitations before summer starts so your guests can make their plans ahead of time.
I love the invitations that open - they have a very formal look. I would say these invitations really represent a black tie event and the outside of the invitation can either be tone on tone for a very elegant and chic look. Or the outside of the invitations can have your wedding color on the outside so your guests know what to expect. Many times the bridesmaids dresses will have shades of this color and is used as accent colors throughout the wedding.