What roof manufacturer are you using? There may be colors that one has that another doesn't. Here's an example of one's options, below the house pic. Can you show or tell us the siding or the actual paint color and the style of the home? The more info you can provide, the better the folks here will be able to help you. I Googled 'sand colored homes with metal roofs' and didn't come up with many, HERE. But by far, my favorite is this one -

When a poster asks about interior or exterior finishes it's always a help to know and understand all of the other finish choices, since they all have to be harmonious with each other. We still don't know what your exterior wall material and finish will be, and that will have a major effect on the color of gutters and downspouts. If your exterior siding and finish will be some sort of "natural" color, then I think the suggestion above to paint both gutters and downspouts a copper color is a good solution. Ron's suggestion of one color for the gutter, matching the natural stain finish, and a second color for the downspouts, matching the siding finish, is also a good possibility. Good luck on your project.

I would try to match the mortar between the bricks. Looks like a whitish gray

@Jon Alan - this is a custom house that we are about to pour the foundation for so the structure is pretty much set at this point. (Thanks for checking first - LOL!) To clarify, the inspiration house was inspiration for colors more than shape/structure. (The inspiration house is in an area prone to flooding which ours is not and we wanted to keep it lower.) As far as a black/gray brick, we really like the warmth of the redder tones and haven't cared for other homes we've seen with black/gray brick so I don't see us going that route.