I have a Mocha Tan metal roof and white vinyl and tan/brown brick front of house. What would be the best trim color for the shutters and down-spouts?
I would definitely advise white down-spouts. These will blend in with the white vinyl and not stand out. You don't want your downspouts to be a main feature of your house, the more subtle they are the better. The shutters on the other hand are meant to stand out. Pick a nice brown that is of the same tone but darker shade than the roof.
You have a very earthy appearance to your house. To complement the Tan/Brown I would consider another earthy color. Depending on the area around your house…. I would try and complement the two. If you are surrounded by lush foliage I would consider a light/moderate brown+green color. Or if you are in a rural area try a more gray+brown color. But if you are still unsure or decide to change the color in the future white would be the one to go. Good luck with the trim, and don't pressure yourself to much.