Pathogenn testing related

Hi every one,
the s.entrica is am streak on XLD plate its normally grow in red colour colonies with black center but suddenly am streak s.entrica on XLD plate its growth is yellow coloured colnonies i dont know how it is possible.

Maccconkey broth was enriched only for E.coli are another organism will be grow ? because am streak positive control E.coli on Macconkey agar plate it will be grow in pink colonies at the same time enriched Maccconkey broth which used of starch sample this Maccconkey broth also streaked in Maccconkey agar plate but growth was observed in like purple colour i dont know its are E.coli or Not if its not E.coli this organism are what.