We installed the backsplash last.
I went to the tile store and spoke to the salesperson there. It was a store that had been around a while, and the salepeople were knowledgeable...not just kids at their summer job, if you know what I mean. They had books to look at with other peoples' backsplash jobs, which was quite helpful.
Our granite is a charcoal gray background, with splashes of peach, lavender and celery green. Depending on the time of day and the amount of light, it can look almost black or almost pewter in color, and the celery green is the color that "ops" the most from it. Our appliances are stainless.
We ended up with white tumbled marble subway tiles in sort of chalky white (so it was a natural looking stone product). For accent tiles, we got glass tiles 1' square in shades of celery green, deeper green, light gray and charcoal gray. With these accent tiles, we did diamonds scattered at various points along the backsplash. The greens and grays in the glass tiles really make the color sin the granite stand out.