The plants you collected from would have been hybrids - crosses between different varieties. So the offspring of them are as various as the different children of two parents. Hybrids do not breed true from seed. But it sounds lovely, enjoy! I collect seeds from my petunias, which started as hybrids and now several generations later have all kinds of colors and markings. I think it is fun to see what shows up. They will always be petunias, or in your case snapdragons.