Kate Middleton wore a pale yellow coat dress to Queen Elizabeth’s Platinum Jubilee in 2022. It was by Emilia Wickstead.
We now know that the then-Duchess wore a modified version of Wickstead’s Elta dress. Both garments feature the same wrap-over front design.
The Princess wore her coat dress in a lovely shade of pastel yellow. Emilia Wickstead, to date, has only sold a ready-to-wear version of the dress in pink, navy and cream, as far as I can see.
Note: In the picture above, I have modified the Elta dress in photoshop to make it appear the same shade as yellow Kate wore, to help anybody scrolling and looking for the yellow garment.