• VSCode Version: 1.18.0
• OS Version: Fedora 26 x86_64

Steps to Reproduce:

1. Add some files in a git repository
2. Modify the .gitignore to ignore a certain pattern, andadd exceptions to this pattern

Extract from my .gitignore:

.vscode/*
!.vscode/settings.json
!.vscode/tasks.json
!.vscode/launch.json
!.vscode/extensions.json

Result:

You can see that .vscode/tasks.json is grayed out because it matches .vscode/*, even if it shouldn't because of the !.vscode/tasks.json rule. However, it still has the correct U badge for some reason.
The file probably isn't supposed to be grayed out, since git does take it into account.