The design should be used to balance out the light and dark shades of the other elements, so if you have light cabinets and countertops, you may want to choose a dark backsplash to bring more depth to the kitchen. If you have very dark cabinets or countertops, a light backsplash will help the kitchen feel fresh.

if you want yellow walls [staying very light?] ...that would make a classic oak hardwood floor really nice for you. and always a quality feature. I might not do black hardware on gray cabs. classic nickel or s/s would just be my preference. If you can work with the background white in the counter I might stick with that for splash and see if a shape would suit the situation...a nice subtle feature.