Paint it the trim color.

Go to a paint store like Sherwin Williams (or wharever) and look at some chips with the 4 or 5 different intensities of color. Play with different shades.

It took me forever to find the ones I wanted.

Finally decided on the Caviar for my windows, I painted my metal roof Halcyon Green, and my 3rd color is rainwashed. The 2 greens are 2 steps from each other on the chip card.

Those 3 colors will be in select spots on my porch railings, trim & rafter tails. My place is red brick with a charcoal mortar.

I wouldn't use more than 3

If you are staying with the house being a light grey, you can go with almost any trim. Since I see that your shutters are a sort of purple color, I would go with a deep plum. And, I would also darken your grey color slightly. Some suggestions...

Whatever you choose for unpainted wood, what do you think about photos showing a painted ceiling in blue or casual fun color, etc.?

Lynnie....she's painting the shutters black & the door red.