Probably caused by https://github.com/xwiki/xwiki-platform/commit/251daf6361885c99773cc979c0e970824560e140. The changes to the `.successmessage` and similar css rulesets in messages.less makes it so that now the default bootstrap background color is overwrote by the color theme object color... For Readable, this default bootstrap background color was given a specific value (from a color variable made for text and not background...). The variables at fault are : @state-warning-text (gives its value to @alert-warning-text in bootstrap), @state-warning-bg (gives its value to @alert-warning-bg in bootstrap) . Need to look further into it to see how we should fix this regression. Some useful implementation notes are available as comments on XWIKI-20986 |