What would indicate that a bacteria species that is successfully stained purple by a gram stain?

Gram positive; Contain thick mesh wall of peptidoglycan in cell wall.

Explanation:

Gram staining technique is used to separate the gram positive and gram negative bacteria on the presence or absence of thick layer of peptidoglycan in cell wall. If a bacteria contain thick layer of peptidoglycan in cell wall it will retain the primary stain crystal violet (purple) and known as gram positive bacteria. If bacteria don't have thick layer of peptidoglycan in cell wall the stain will wash out and it will give the pink color known as gram negative bacteria. Peptidoglycan is glycoprotein or Glucose+Protein.