fill svgs with currentColor

This can be overriden, but will make sure that a disabled button has a lighter grey icon, rather than the current black

This is mostly in case when _no_ css is loaded

The issue does not name a file, test, or entry point. Start by locating the SVG assets and disabled-button styling in the frontend, then verify how the icons render when no CSS is loaded; done means disabled-button icons use the current text color and appear lighter when disabled.

Written by the indexing model from the issue text.