The grey level on Ubuntu is feinter than on Windows as to be difficult to read. For example in SliceViewer in the top box for tracking info.
Great point! I must admit I’ve not paid enough attention to how readable things like this are across different OSs. I’ve made an issue for this: Sliceviewer data table text not contrasting enough · Issue #29522 · mantidproject/mantid · GitHub
I had noticed it some time ago when I clicked on a ws for info but forgot to mention it!