I'd do the concrete several shades darker blue than your siding. A navy, but make sure it is in the same color range as the siding, not warmer or cooler. I might to the same color on the garage doors, so they recede, not attract attention. I think white to match the windows would look good for the trim.

Some visual

Your house is red white and blue???? Yuck.

I'd paint the base white and add a wire trellis with climbing vine as you see in the photo below. I would NOT add the red.

My house is a blue with a faint green tinge with white trim and a wine red door. It does not read at all like the flag. It looks great. My neighborhood is full of blue houses with white/cream trim, some with red doors. Blue with white trim and a red door is a pretty classic look.