Prince Harry and Meghan Markle's royal wedding will take place in exactly two months in the St. George's Chapel at Windsor Castle on May 19.

More than 2,600 guests are invited to the royal nuptials, including 1,200 members of the public who have served their communities.

The guest list also reportedly includes the likes of actress Priyanka Chopra, Markle's Suits co-stars, and tennis champ Serene Williams among others.

Since it's a royal affair, a certain amount of etiquette is required to be followed by the guests, particularly when it comes to dressing up for the occasion. Debrett's, an etiquette and behavior school in the UK, has now made a list of what guests should or shouldn't wear to Harry and Markle's royal wedding.

No Monochromes

Although black is the go-to color for many, it's a complete no-no for the royal family as it's the color associated with mourning. White, on the other hand, is taking things too far like one wishes they were standing at the altar, according to the coaching company.

Debrett's also points out that guests should avoid bright colors and patterns as they may dominate photographs and guests should take special care to make sure they don't outshine the bride.

The company also suggests that if guests still want to go ahead with a monochrome look, they should check with the bride and the groom before making that decision.

Avoid Wearing The Same Outfit

Outfits for weddings don't come cheap but if one is attending an event that will be covered by media around the world, it would be wise to invest in a new dress.

The guide notes that if one doesn't want to splash the cash on a new ensemble and decides to repeat an outfit, they must change things up with a different hairstyle or choice of accessories.

Wear A Hat

The UK's obsession with hats at weddings could be baffling for American guests, but they are considered as traditional, which can add a sense of occasion and fun to a wedding outfit.

Debrett's also says that one can wear fancy headwear but it shouldn't hamper kissing.

Dress According To The Weather

Even though Harry and Meghan's wedding is in May, it's England after all. It may be a May wedding for Harry and Meghan, but this is Britain, after all.

Debrett's explains that sometimes people forget to question "whether bare legs and shoulders are really appropriate when the temperature gauge is hovering somewhere between Baltic and Arctic."

The guide advises that people will feel more comfortable in clothing that is appropriate for the weather, which in turn, will make them feel more confident.

"Dress for the actual weather, rather than ideal wedding weather," Debrett's notes.

Tags: Prince Harry Meghan Markle Royal Wedding