Depending on how you wear it, I think this color combination can come off as either youthful and casual or more elegant and sophisticated (without being stuffy). I think J.Crew is doing this trend particularly well right now -- some of their sweaters and jackets in particular are absolutely lovely and the J.Crew floral skirt on the bottom right seems very reminiscent of something Michelle Obama would wear. The yellow/gray combo has also been popping up a lot in home decor and other forms of design. I love these stationery sets from two of my favorite sellers on Etsy (In-vita Paper Studio and Made by Michelle Brusegaard, respectively):
On the home decor front, yellow/gray is popping up in a lot of accessories -- particularly pillows and rugs and is also appearing in a lot of modern fabrics (see Amy Butler for some lovely examples). When paired with white accessories, this color scheme can really pop. I particularly love the Jonathan Adler rug and the bedding from Omhome (both shown below). Perhaps I can find room for them in my next house (the current one being rather full).
