Currently, filewarning features a non-standard color not part of the WikimediaUI color palette.
It's already featuring the warning icon, so we can apply the standard treatment of inline warning messages with Base0 color.
Example URL: https://commons.wikimedia.org/wiki/File:Sample_Syllabus_for_Wikipedia_assignment.pdf
Another quirks is the added padding, which looks unintended as long as user isn't interacting with the link.
Proposal
Proposal is to reduce the padding-right to 2px
