I don’t think any appointed strata manager is going to get into aesthetics. They will either just paint like for like or, if they are feeling generous, ask for a majority opinion, so you are back where you started.
How about getting someone who’s handy with photoshop to take a picture of the block and show it in different combinations of colours? It might change a few minds.
A lot of people have little visual imagination and want things to stay as they are because they can’t picture anything else in their mind’s eye.