I think one of the most stunning wedding themes is going Moroccan. It's often characterized by rich colors like shades of red, purple, blues, and orange, and often is a combination of those hues. Patterns are intricate yet festive, with inspirations from Arabic and Asian cultures. I would say having a Moroccan wedding theme is all about the details, from the decor to the invitations to favors.
While going for a Moroccan theme for your wedding would entail coordinating the details, it's not that hard. To start off, you could browse for pictures of Morocco and try recreating the look with what's available in the market. I've made an inspiration board for a Moroccan wedding theme, and I hope this will help get you started:
Top row, from left: Purple Floral Beaded Window Valance from SaffronMarigold.com; Stacked Wedding Cake from TraceysCakes.co.uk; Purple and Gold Scroll Invitation from MajesticInvites.com.
2nd row, from left: Belt details of Style W2322L from RayliaDesigns.com; Moroccan Tealight Candle Holders from FavorsAndFlowers.com; Purple Beaded A-Line Dress from Jovani.com; Cher wedding gown from Pronovias.com; Style AV9691 bridesmaid dress from JLMCouture.com; 17in Zaarni Organza Wrap Circles from Bellenza.com.
Bottom row, from left: Spectrum Chandelier from UrbanOutfitters.com; Wedding bouquet by Studio Sweet Pea, NYC from InstyleWeddings.com; Large Wedding Tent from HaremNights.co.uk.