Popup background color should match the diagnostic result
Currently only the content inside popup is marked as red in case of errors / warning / info
Current Behaviour
Expected Behaviour
You can adjust the style by creating an LSP folder inside of your Packages directory ("Preferences: Browse Packages") and copying the popups.css file into that folder. This would create a local override of that file. Note that ST needs to be restarted before changes in that file get applied.
In particular the line at https://github.com/sublimelsp/LSP/blob/85c04599854fb3ee9870e8ab0272d0c153836957/popups.css#L2 is responsible for the padding. Note that there can be additional content in the popup, like code actions, hover documentation and links. The code that creates the content of hover popups lives in https://github.com/sublimelsp/LSP/blob/85c04599854fb3ee9870e8ab0272d0c153836957/plugin/hover.py.
If you found a style that works well in all occasions, feel free to create a pull request with the improvements.
Not sure I understand what the issue is about... Is it that the text color is yellowish?