@epriestley Inverting the "old" (greyscale) icons would resolve my issue.

They're used in a diff. Red means someone has rejected my most recent diff. Black means they rejected an older version but haven't seen my newest revision.

I think this is a feature request, but feel free to switch projects if it's a bug.

Is this still being worked on? I would love this feature.

I don't know RuboCop well enough to definitively answer the question about whether that mode exists, or to volunteer to maintain the driver. But I opened a parallel issue in the RuboCop repo, so hopefully we'll find out whether RuboCop has this mode soon enough.