Does webkit-scrollbar work with webkit-transition?

I want a custom webkit-scrollbar to animate a different background color for the hover state. The code below changes the color on hover but doesn't animate anything. It works on a div so I suspect webkit-scrollbar doesn't play nice with transitions.

::-webkit-scrollbar-thumb {
    background-color: #a8a8a8;
    -webkit-transition: background-color 1s linear;
}

::-webkit-scrollbar-thumb:hover {
    background-color: #f6f6f6;
}

What can I use instead of webkit transition?

Use the @supports (transition) feature query instead.

What does webkit transition do in CSS?

-webkit-transition is a non-standard boolean CSS media feature whose value indicates whether vendor-prefixed CSS transition s are supported or not. This media feature is only supported by WebKit. The standards-based alternative is to use a @supports feature query instead.

What is the use of Webkit scrollbar?

::-webkit-scrollbar is a pseudo-element in CSS employed to modify the look of a browser's scrollbar.

No, it is not implemented. We should file a bug on http://bugs.webkit.org/