dappled

spangled

marbled, moiré (or moire), veined

chromatic, colored, colorful, motley, multicolored, multihued, polychromatic, polychrome, prismatic, rainbow, varicolored, variegated

blotched, blotchy, piebald, pinto, roan

shaded

checkered, motley, multicolored, polychromatic, polychrome, varicolored, variegated

blotted, brindled (or brindle), calico, specked, speckled, streaked

colored, colorful, pigmented

dotted, peppered, sprinkled

stippled

discolored, dyed, marked, stained

flecked, streaked

bespattered, spattered