Better visualization of derived roles

When creating a role by deriving it from an existing one, the role overview shows a column "Modifications", giving the number of permissions deviating from the source role. When editing the derived role though, it is hard to see what changes have been made: You have to scan hundreds of permissions and find those not in state "default (yes)" or "default (no)" but instead "yes" or "no". Please find a better way to visualize the differences between derived roles and their sources. For example: Highlight non-default permissions and the category headers that contain them.