I'm working on this issue (that I created) : https://youtrack.jetbrains.com/issue/IDEA-146984
I fount that the class who manage a part of missing options is :
to add missing fallback attribute key, but the problem is they are in two different modules. CodeInsightColors is in "core-api" module, and "DefaultLanguageHighlighterColors" is in the editor-ui-api module, and both modules are not dependants. Solution I fount is to move "DefaultLanguageHighlighterColors" and "HighlighterColors" to "core-api" module, but as it's an API, i'm not sure I can just move them.
What shoud I do exactly in this case ? Note that what I did should solve the issue (I have to check for possible missing items though).