One lady I work for has cosmos that look like your purple. She also has some that are pink. Are they suppose to come in pink?
The orig. pic in this discussion looks pink to me. They do come in other shades though, and white/off white. https://www.gardenstew.com/plantstew/37162
Years ago I grew cosmos. They would re-seed and come up year after year. I do miss them. Simple easy flower.