Forcing the colour of the chat discussion pane (pop-up mode)
From MoodleDocs
Where the background colour of the chat pane background is inherited and is difficult to read e.g. the colour makes it hard to see the text. The colour can be forced using the following in your theme's CSS.
html {
background: none !important;
}
body.mod-chat-gui_header_js {
background-color: white !important;
}
The above example makes the background white.
(Derived from this discussion in the Theme forum)
