Unknown and invasive flowers

Hi y'all! These are growing invasively all over my yard. I'm frustrated trying to pull them up, because I can never get all the roots, so I've decided to live with them. The question is, what are they? There are three phenotypes: all-white, all-fuschia, and variegated (as in the attached photo.)

Thanks!

 

Catharanthus?

 

looks a little bit like rosy periwinkle ?

 

http://www.botany.wisc.edu/garden/db/speciesdetail.asp?genus=Catharanthus&species=roseus

 

That'd be it, alright. Thanks, guys!