Kate Middleton and Meghan Markle combined two nude nail polishes and used them for their respective wedding days. A fashion expert claimed that this was against the royal protocol, which does not permit bright and dark colors.

Speaking to Express UK, Daena Borrowman of jewellerybox explained that royal women are not allowed to paint their fingernails with such tones. She added that "only nude shades, sheer whites, and light pinks'' are permitted.

But, it appeared that the Duchess of Cambridge and Duchess of Sussex wore bright shades when they became official members of the British Royal Family. As reported, the latter mixed the Negligee and Unmasked colors from CND Shellac, while the former combined Bourjois' 28 Rose Lounger and Essie's 423 Allure.

Apart from their respective wedding days, the expert noted that Kate Middleton and Meghan Markle have "occasionally favored" darker shades, as well. This is reportedly especially true on their open-toed heels as they have worn "red or oxblood toenails" in the past.

Meanwhile, Queen Elizabeth II is said to have used only "delicate, translucent" tones for her nails. Some alleged that she finds colorful nail polishes "vulgar," including even the traditional classic shades.

As for her long-time favorite, she loves Ballet Slippers from Essie. A hairstylist of hers requested it in 1989, and she has since remained a fan of the shade.

But, did Meghan Markle and Kate Middleton really break a royal rule when they wore dark or bright colors for their nails? Royal experts do not think so, with one stating that "nail polish has nothing to with protocol," according to Town & Country.

Victoria Arbiter shared on social media that the color of nails, as well as tights, messy buns, and car doors are irrelevant when it comes to royal protocols. She emphasized that it is all wrong, and the nonsense has to stop.

Marlene Koenig echoed the statements to the publication, adding that "there are no books, no rules" about what a royal can wear in terms of their nail polishes. Moreover, the two Duchesses are not the only royals who do it as "royals around the world" have, also, worn similar shades.

Whatever the case, though, reports said that the rule in nail polishes is not the only royal style protocol that Kate Middleton and Meghan Markle have broken as a member of the British Royal Family. Hello! previously listed some of the instances when the two Duchesses, alongside other royal women, failed to follow a few "unspoken" rules.

It includes the future Queen Consort's pair of cork wedges, above-the-knee skirt, and strapless dresses. As for the former actress, the list features her hatless engagement with Queen Elizabeth II and bare-legged appearance in an official outing.