Since nobody else has taken this one, I'll try.
They might grow true, but they'll probably cross, especially if they're close together. Maybe you'll get better help from someone on the Cottage Gardens forum...

Yes, Most likely they will not. Besides them being close together and most likely crossed with one another; The supplier of the plants you got probably does not keep them seperate and his/her hollyhocks have crossed so many times even if you did keep them completely seperate the seeds would be different colors.(usually indicated by the tag saying mixed; ones that are named and do not say mix will most likely produce true from seed if colors are kept seperate.)
Hope this helps
Mike aka plantsofheaven