You can make your own easily. The cone is simply a long triangle, with 2 or 3 scoops of differently colored ice cream on top. Cut them from paper and recut till they look good to kids. Coloring books are marvelous for simple shapes.
The ones I've made mostly have come from old scrubs, which have such lovely, clear colors. And old sheets, marvelous what colors they come in, along with patterns on them. Really surprising how pretty they are, and cheap in thrift shops and church sales.