I would stain the flooring, paint can peel and be a bother. For me, I'd stain it dark but that's a personal call. Painting a bright green when the rest of the colors are muted may be too much pop. How about a light green that is in the historical colors so it's muted a bit. I love apple green but muted a tiny bit.

I would paint all of the trim to match your siding. It would be a much softer color than white especially with the brick and the brick accents. I think you could go with a blue door.

absolutely no shutters. Why muddle up the look of the exterior when he already has 2 siding colors, with 2 diff siding materials, brick, white trim and a charcoal/greenish roof? here. does this look good? (give me a pic straight on and I'll photoshop something better, but it still won't look good! for the front door, He might try looking for a deep olive green with some bronze undertones Like this color on the left replacing the bright bench w/a wood verision, and getting some numbers clearly displayed. you'll have to enlarge this to see everything He could always paint that white one, add some colorful outdoor pillows. I also like all of these wood and copper accents, along w/these paint colors, address plaque, and even a slight limewash on the brick I know you said he doesn't want to paint. but a very light limewash w/Romabio would give this similar effect. (AND, if will completely wash off within 72 hours if he doesn't like it. there is no upkeep w/this, it's natural liime and will patina w/time. Just a suggestion) could also go darker w/the Urbane Bronze, Iron Ore, or one of those dark bronze/black tones Or, maybe you want to go w/a brick color front door. maybe a door w/some lites in them rather than solid this door style might be nice. you could even have smaller glass panels.

Thank you for comments. Landscaping later. Realize landscaping is needed. Not telling you guys anything new...vinyl siding fades over time, so removing the shutters will reveal the difference and stick out like a sore thumb. I am thinking a  deep blue on shutters and door and paint coach lights a black. Garage door same color as siding. There are so many beautiful blues, even the lighter slate blues have appeal. Do not like brown. Following paint, will landscape and pick up some accent pots in sane color as door to off set garage.