There are tons of colors and patterns, but to name some: butterflies (The edging on the fins is a different color from the body; usually cellophane), cambodians (light bodied bettas with solid colored fins), dragons (A thick scaling), metallics (A shiny, thickish scaling), red, royal blue, steel blue, turquoise, pineapple, copper, black, black melano (Blue body w/ black fins), black orchid (Black w/ blue iridescence), bi-color, multicolor, mustard gas, gold, orange, etc.
My avatar is a black butterfly mustard gas. The bettas in my sig are metallic green marble, cambodian, mustard gas, and royal blue.