Dicks will not have all black.
You have two choices, buy off the shelf and color in with permanent markers & liquid polish or buy from one of the official supply merchandisers. Most have reasonable return policies if the shoes you purchase don't fit.
Eastbay's web site allows you to dial down style, size, width, and color. Zappo's has officiating style shoes also.
I've seen one official wear a pair of golf shoes and he is retired now.
Turf shoes, of which baseball trainers/coaching shoes compare, will work fine on turf and well groomed grass fields. If your area has "cow pastures", you will want a pair of molded football cleats at a minimum.
Do not skimp on footwear. If your feet hurt or get messed up, your officiating and enjoyment will suffer. Years of battling plantar fasciitis, shin splits, and old ankle injuries have me constantly on the look out for the best shoe.