found when testing T351097: Suggested edits images in dark mode are in inverted colours
Steps to replicate the issue (include links if applicable):

• Enable dark mode, i.e. "Dark mode toggle" on Special:Preferences#mw-prefsection-gadgets on testwiki or enwiki
• Go to Special:MentorDashboard page

What happens?:

• the icons in "Your mentees" table columns titles are barely visible
• the icons in "Send praise" module have the same issue

What should have happened instead?:

• the icons should be visible in dark mode, e.g. Special:Homepage Impact module has icons with good contrast: