I have just updated my iMac (not the 2008 in my sig, it's officially supported) from Yosemite to Sierra. However I have noticed a strange UI problem. In Yosemite, the search bar, and buttons such as back/next in Safari appear a very bright white. In El Capitain and later, they are a darker color with some grey gradient. For some reason I still see them in very bright white on Sierra. This appears in all apps. Anyone know why this is?