The differences are small yet significant.
Kate Middleton Princess Charlotte Royal Wedding
Credit: WPA Pool/Getty Images

Meghan Markle's wasn't the only dress to grab our attention at her May nuptials to Prince Harry. Kate Middleton, whose seemingly bold choice of attire also made more than a few headlines, had us talking for days as well.

Did she really wear white? Haven't we seen her in that look before?

Royal watchers were quick to notice that Middleton's pale yellow coat (which fell startlingly close to white on the color wheel) looked a lot like a white Alexander McQueen coat she had previously worn to both Princess Charlotte's christening and to one of the Queen's birthday jubilee events.

But it turns out, thanks to the detective work of one eagle-eyed fan, it may not have actually been the same dress. Gasp!

An Instagram user behind the account titled "Royal Addicted 2," noticed a small yet significant difference between the two looks: the coat Kate wore for Harry and Meghan's wedding had tiny buttons on the cuff of each sleeve, while the other did not.

The post also pointed out that the dress Middleton wore to the royal wedding was a "primrose yellow" color, while the one she wore to previous events had a "cream" hue.

WATCH: You'll Want To Steal The Royal Photographer's Trick To Get Smiles From Your Family Members Too

Phew! Glad we settled that!