Meg, where are you located? Can you have a paint color mixed for you, or do you have no choice other than "color wheel" paints available?

Are they real stone or are they ceramic, cement or porcelain based products? If they are stone, are they sealed? If so, with what? These are the questions that you will need to offer before we can suggest any form of treatment. You can always (hire a professional and have him/her) sink them in cement and then stain the cement! That could be fun...and expensive.

I love color but I also like monochromatic and neutral color schemes. When I go neutral, I add lots of texture or some glitz with shiny objects. My cream and dark brown master suite is decorated with lots of gold and silver. It's lovely and calming. Tip: if you want to see different color schemes just search by color in houzz, i.e., blue bedroom

Can you strip the paint from the copper gutters? I think the contrast of the warm copper against BM Ocean Floor siding could be pretty stunning. Regarding the front door, I think a navy (like BM 2059-10 Marine Blue) or a greyish teal (like BM 777 Summer Nights) could also look pretty grand.