Macro cannot find shading colour black

[macropod]

The colour 'black' is found when searched for 'yellow' by you, because the search for black is too generic inside the Word's internal coding

Not so. There is a bug in the interaction with Find and BackgroundPatternColorIndex/BackgroundPatternColor. A Find for wdBlack Finds everything that doesn't have a Background Color. A Find for wdYellow Finds both Yellow and Black. The workaround is do a Find for wdYellow and to apply an additional test to determine which of Yellow and Black it is. That's what the code I posted does.