I like @kelly's idea of picking a lovely fresh color of paint for the door. You can then bring it down onto the stair risers. Either a solid color to match the front door, or go wild and add some decorative elements to the risers with stencils. Or think of staining the door a great color and coordinate the stair railings and risers. I have an idea book put together for just such project that might spark some ideas for you. http://www.houzz.com/ideabooks/16700983/thumbs/Kathryn-Delany-s-Decorative-Stair-Risers

I just found out that blue green colors really bring out the beauty of wood. I know its not the same but I have honey oak cabinets and just repainted my kitchen a blue green and it really made the cabinets look stunning. Maybe you could try something in that color family to enhance the wood. Just a thought.

All the suggestions above are perfectly good. However, when you have a house that is entirely painted, the options are so endless that it's easy to get stuck. I'd advise either finding photos of comparable homes in colors that you really love, and reproducing a similar palette on your home… or upload a picture of your house to a colorizing site, and play around with various combos. Sherwin Williams has a Color Visualizer that is decent. I don't mind a white house, but feel that the black trim is a bit harsh. On the railing especially- it feels like it is outlining itself too much. Reduce the contrast between the body and the rail and it will enhance the house rather than overwhelm it. You have a lot of choices, so just experiment and go with what resonates with you.

Oops! Your trim looks grayish blue to me. Sorry, didn't see it is charcoal until afterwards...well in that case, I think I would still do gable and wrought iron as mentioned but then try a bright yellow, like SW's BEESWAX is paint color. Are you in the islands? Sorta has "that look". Envy : )