Hi Nathaniel, The "problem" are these lines <https://github.com/Jermolene/TiddlyWiki5/blob/6c6b723a0d0ffb3456994e76d6bc4d0bc3f37329/themes/tiddlywiki/snowwhite/base.tid#L89-L95> in the default SnowWhite theme. The SnowWhite theme uses a gradient for the tab buttons, for which the colors are not exposed in the palette editor, whereas I think they should be.
Tip: If you switch to the Vanilla theme, you won't run into this problem and get a proper contrast. Best wishes, — tb -- You received this message because you are subscribed to the Google Groups "TiddlyWiki" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/tiddlywiki. To view this discussion on the web visit https://groups.google.com/d/msgid/tiddlywiki/8c04386b-7dcc-4a66-99cb-a5240a2b7ba0%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.

