IMO you need to remove one of the finishes so either the brick or the slate needs to go, Not painted just gone. I think in this case the brick should go then sjust siding and the slate to deal with I would do a dark charcoal for the siding and a introduce some natural cedar for maybe the garge door which BTW should be a MCM style and the front door in the cedar too. Then landscaping to give you that MCM feel this is one I use for inspiration often

I think your home is very charming! I wouldn't paint the brick but would paint the siding a color that corresponds with the stone. I understand that's easy for me to say since I haven't been looking at your home for 25 years. I would just hate for you to paint over some of the charm of your beautiful home.

Okay, I gotta admit that the all-grey color scheme, even on the brick does look nice. It just really changes the style of the home.

Hope this helps in your decision-making!

^^^ Both of these looks are great.