Julia, I just want to make a few comments using photo one and five to make my points.
In picture one, your maroon pot looks great with the plants and the plants look great with the pot.
The plants in the other pots look great, but the pots themselves look yucky and so the entire look is compromised.
In picture five, the grey pots near the house look great with their plants as the pots next to each other are uniform in color and the plants contrast nicely with the color of the pots.
The green pots far away look great but can't tell what is in them because the plants are very low growing and the pots are in the shade.
I am not a fan of green plants planted in green pots unless the plant color is very much in contrast. That's why I think all the dark foliaged plants would look good in your green pots but not in pots that you paint brown. Same for pots that you paint brown: plant the lite and bright colored plants in them i.e. look at how well the plants contrast within the maroon pot in photo one.
Thus, I think that the color of the plants in a pot should be considered before you decide which color to repaint the pot. Good to have 2 colors of paint to accommodate the varying plant colors of your extensive garden.
