When checking a few pages in the context of #3163810: [META] Assess conformance with WCAG SC 2.4.7 "Focus Visible" I've noticed when testing the Tour module on a Views edit page that there is a green as well as a white focus outline for a link which looks kind of odd and distracting. It turns out it is because of box-shadow using white along green as colors. For Claro that pattern works out well since the general background color is white and therefor the focus outline creats some sort of white "padding" to the element it is highlighting, but as soon as there is a black background that default becomes kind of problematic.
a) Tour tooltips (fixed in #4)
The following screenshot illustrates the issue for Tour tooltips
In the subsequent screenshot I've just replaced the color white with black in the devtools to illustrate how the focus outlines looks without the second white outline:
b) admin messages
Admin messages containing a link like this warning message have the problem as well
Those are the occasions found so far. If there are more please update the IS accordingly