Louis' outfit of choice was actually first worn by George all the way back in 2014 when the eldest child paired them with a red sweater while on an Australian royal tour with his parents. The shorts reportedly sold out in 24 hours following George's Australian appearance. It seems even Charlotte has worn the shorts, as she was photographed wearing either them or a very similar pair in 2016.
Louis' outfit wasn't the only story of the day! In a video posted to Kensington Palace's Instagram, fans also got to see the tot walking as he explored the gardens, which he and his siblings helped their mom to create by gathering moss, leaves, twigs and hazel sticks.
In the video, Kate emphasized the importance of kids playing outdoors and expressed her hope that the garden will be a place for "families, kids and communities to get outside, enjoy nature and the outdoors and spend quality time together."
"I really feel that nature and being interactive outdoors has huge benefits on our physical and mental well-being, particularly for young kiddies," she said.
Previous pics from the family's visit show little Louis in motion as William, dressed in brown pants and a light blue shirt, watches on. Kate, wearing a floral & other Stories maxi dress, also spent her time with her youngest child, hugging him as he examines a rock.