SVG currentColor
Code
Color transitions on SVG paths can be tricky, as browsers behave differently when it comes to transition property color and fill. Especially when currentColor is involved.
This was something I would have needed for the navigation on this site, but I ran into browser issues. In the end I used a slightly different solution and specified a handful of actual color values instead of using the currentColor shortcut. But I made this pen to check if browser behavior changes over time.