Typical mass-produced wheels look okay on many toys, but if you want wheels that look more like the real thing, try this. First, drill out the center of a purchased wheel using a ⁷⁄₈ " Forstner bit. Dye the resulting tire black. Then, cut a ¹⁄₂ " length of ⁷⁄₈ " dowel and drill an axle hole in its center. Dye this wheel rim a contrasting color or leave it natural; then, glue it into the center of the black tire.  
—Matt Wellington, Temple, Texas