This was originally brought up at en.WP VP proposals#Darker section titles in page history. A subsequent commenter noted that the text was not even AA compliant against the background (except with 18pt font).
We think we've found an acceptable AAA-compliant color with #585858. My recommendation would be the lightest-gray that achieves AAA compliance, and #585858 just happens to be the color on which we settled.
One of the issues with increasing the autocomment's contrast to the background is with the following .comment text, which is the edit summary-proper. We've been exploring ways of increasing the contrast between these two texts also:
- Change .autocomment to straight letters
- Change .comment to straight letters, setting CSS for .autocomment to italics
- Change .autocomment to use font-weight: lighter (seem to work against desire to increase contrast).
There may be other styles to explore in that regard.