I am looking for the single to semi double, leggy types that bloom mid October to Thanksgiving in the south. They don't get mildew, boitrytis, or any other dread disease and are surprisingly hardy. The color range is pale pink to a deep wine, and yellow through a dark gold to rust. The flowers form in loose sprays and the plants needed staking.
I had a selection of three or four colors but lost them three moves and seventeen years ago. I have been looking for replacements ever since.
Bluestone Perennials has Clara Curtis and they used to have Mary Stoker - don't know if they still do. Those are 2 of the most common old fashioned mums.
If you search on that I think there are several more varieties. Clara Curtis is the most popular but Mary Stoker is also beautiful - like little flames of pale yellow to orange at the center.
Maybe you are referring to Korean mums. They are very variable, tall, bloom late, and easily grown from seeds to flower the first year. Do a search for Korean mum seeds, there should be vendors if not here in the USA, definitely in the UK.