Q. Can someone change his minhag of having black stripes on his taalis and just use a taalis that is totally white?

A. See questions 1507 snd 1508. Daas Noite (283, p. 146) rules that one should not change his minhag.
Horav Shlomo Miller’s Shlit’a opinion is that also one should avoid dressing in a taalis different from the rest of the congregants, as he may become the focus of ayin horah or evil eye. (See Baba Basra 30)

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a