139381 2014-12-07 18:30:22 -0800 ::-webkit-scrollbar continues to not support transitions 2023-05-10 10:47:26 -0700 1 1 1 Unclassified WebKit Animations 528+ (Nightly build) PC Windows 7 RESOLVED WONTFIX P2 Normal --- 1 Sean.Palmer.Anderson webkit-unassigned dino graouts oldest_to_newest 1053263 0 Sean.Palmer.Anderson 2014-12-07 18:30:22 -0800 Transitions became supported on pseudo-selectors fairly recently. However, transitions do not appear to be supported on the ::-webkit-scrollbar (et. al) selectors. I expect background-color to transition when hovering over a scrollbar with a transition applied to it. Example: http://codepen.io/Meo/pen/EaPvwV Code: <div class='parent'> <div class='child'> </div> </div> .parent { height: 100px; width: 100px; overflow-y: scroll; overflow-x: hidden; } .child { width: 200px; height: 200px; } ::-webkit-scrollbar { width: 8px; } ::-webkit-scrollbar-thumb { transition: all 5s linear; -webkit-transition: all 5s linear; background-color: blue; } ::-webkit-scrollbar-thumb:hover { background-color: gray; } 1954379 1 graouts 2023-05-10 10:47:26 -0700 I don't think we want to add support for transitions for ::-webkit-scrollbar or generally improve that feature. Marking as WONTFIX.