The royal rule Pippa Middleton always follows - even though she doesn't need to

There is a royal rule Pippa Middleton always follows when she is out and about attending public events - even though it doesn't apply to her.

• Pippa Middleton is often snapped at public events and engagements with members of the Royal Family.
• Although she isn't a royal, there are still some protocols that Pippa always follows for these events.
• In other royal news, have you seen Kate Middleton's upper arm trick to ensure her arms look toned in every photo?

There is an unofficial royal protocol that dictates that women in the Royal Family have sensible short nails without bold colourful varnish, sparkles or any kind of gaudy embellishment. This is a unique rule that Pippa Middleton always follows as she only ever steps out to events with pale pink short neutral nails that look manicured and demure. 

Most recently, Pippa has attended publicised events such as Wimbledon, the King's Coronation and her sister's Christmas carol concert at Westminster Abbey. At each of these events, the Princess of Wales's sister has been snapped with pale pink short nails.

It could be that Pippa prefers this style of nail, or it might be that she is also following this royal rule that is in place for her sister and other women within the Royal Family. 

Royal commenters have spoken about this royal protocol before and have revealed that there isn't a rule against colourful nail polish, but there is a strong encouragement that royal women have 'appropriate' nails. "There’s no actual protocol about dark nail polish," royal correspondent and author of the book, Finding Freedom, Omid Scobie told Harper's Bazaar. "It’s simply about being appropriate—we’d never see this [dark nails] at a royal engagement. "

It seems that Pippa's go-to varnish is the same as her sister, Kate Middleton's favourite nail polish. It was revealed a long time ago that the Princess's favourite shade is Essie's pale pink shade called 'Allure'. The shade was then discontinued but it has been reported that the Princess uses 'Ballet Slippers' in its place. 

This is the same shade that has been rumoured to be Queen Elizabeth's favourite nail polish. The pale pink colour of 'Ballet Slippers' is the perfectly appropriate look that makes nails look perfect and healthy without drawing too much attention or looking ostentatious or tacky.

The Princess of Wales's sister wears this neutral nail style with all of her looks, no matter the season. Pippa Middleton's white ruffled dress with delicate flower patterns was the sweetest summer dress we've ever seen and she opted for a translucent pink varnish to accompany this look. Similarly, Pippa Middleton's twinkling champagne dress was the perfect wedding guest look, and she opted for another delicate nail colour to match her bold dress.