I come by my love for yellow naturally, as it is my mother's absolute favorite color.  I think of her when I see the color, and I'm sure I always will.  Grey is one of my personal favorites, so the combination of the two seems like a natural choice.  And it's a really popular color combination right now, which is just fine with me.  Here are a few of my favorite grey and yellow picks:
Left to Right, Top to Bottom
Charlotte Cardigan by Tinley Road -
 Piperlime: $69
Left to Right, Top to Bottom
Brightness in Shimmering Shadows Necklace - 
Elva Fields: $268
Customizable Keep Cup - 
Keep Cup: $8.50 - $14.20 
(price varies by size)