This little patch cures the problem
svn diff twikiplugins/ActionTrackerPlugin/pub/TWiki/ActionTrackerPlugin/styles.css
Index: twikiplugins/ActionTrackerPlugin/pub/TWiki/ActionTrackerPlugin/styles.css
===================================================================
--- twikiplugins/ActionTrackerPlugin/pub/TWiki/ActionTrackerPlugin/styles.css (revision 8378)
+++ twikiplugins/ActionTrackerPlugin/pub/TWiki/ActionTrackerPlugin/styles.css (working copy)
@@ -36,6 +36,6 @@
}
/* Warning style (e.g. late action) */
-).atpWarn {
+.atpWarn {
background-color: yellow;
}
SVN 8385
CC