Sorry, but would you really take advice from someone that hasn't seen even off color photos of all the materials you've selected or knows the floor plan of your kitchen. If you post photos of the color and door style of the cabinets and cabinet moldings, a photo or the the name of the coutertop (there are many types and styles of black countertops), the finish and style of the appliances, the flooring you have selected, and the floor plan of your kitchen, maybe you could get sensible advice along of course with a lot of less valuable input. Asking blind strangers to direct you isn't sensible.

A soft, warm grey shade would look lovely, and can be as dark or light as you want. A warmer shade will work with the brown stained wood floor, and the grey will complement the black granite. You could have an undertone of green, blue or tan if you didn't want a pure grey. And it would look nice with any silver metal hardware, either polished or satin/brushed, so you could choose pewter, chrome or nickel. It would still work with white trim too.

actually, to brighten up this dark and small feeling space, i'd look for a creamy base colored stone like khasmir gold or ivory gold, being sure to add an overhang on the island (if you like movement in the stone check out juprana granite) then exchange the pot rack over the island with either a pair of great pendants or a statement chandelier. from my own kitchen remodel experience i'll share you with you this: you'll get a much better price from a granite company then you will from a large home store ;) and be sure to take a cabinet door with you to shop. you can continue the granite onto the wall as a backsplash...they can cut the stone and make it go higher up the wall than the standard 3 inches which can be a great look. but if you really want tile, go for something simple that won't compete with the granite....like a cream colored subway tile. you can apply thim in a running brick pattern or a more modern stacked geometric pattern or even a herringbone. to control staining from food prep, don't use a white grout, use a slightly darker grout color that is inspired from the stone countertop. just remember that using a pattern on the countertop and another pattern on the backsplash can easily become overwhelming and then neither element stands out as the focal point. if you are spending a lot on a granite countertop, do everything you can to make it stand out as the best feature.

Bet your farmhouse kitchen is cheerful and delightful! I'm curious what colors you have in the adjacent living room. Are there any fabrics or unique accent items you'd like to have more attention? Feel free to bring a pillow or quilt or pottery piece from the living room to your yellow tile to get a feel for what color might capture your heart. Will it be a mellow, blend-in kind of look? Or something that adds a "pop" to your rooms? Cant wait to hear your discoveries!