Question: what is the colour of gram positive bacteria
[{'answer': 'violet', 'provenance': [{'wikipedia_id': '12935', 'title': 'Gram stain', 'start_paragraph_id': 2, 'start_character': 212, 'end_paragraph_id': 2, 'end_character': 218, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]