Now that the standardized <meta name="color-scheme"> and the corresponding CSS property color-scheme have landed in Chrome and Safari, an accessibility issue around link colors occurs:

The colors defined in §14.3.4 Phrasing content…

:link { color: #0000EE; }
:visited { color: #551A8B; }
:link:active, :visited:active { color: #FF0000; }
:link, :visited { text-decoration: underline; cursor: pointer; }

…do not have sufficient contrast on a dark background. See this demo (note the [Top] links):

This issue should probably also affect the definition of the CSS System Colors:

• LinkText (contrast insufficient): Text in non-active, non-visited links.
• VisitedText (contrast insufficient): Text in visited links.
• ActiveText (contrast OK-ish): Text in active links.

I have also opened bugs for Chrome, WebKit, and Firefox for awareness and to get this fixed.