Final answer:
The color of Mycobacterium after the addition of the secondary stain is red.
Step-by-step explanation:
The color of Mycobacterium after the addition of the secondary stain is red. The secondary stain used in the acid-fast staining procedure for Mycobacterium is methylene blue. Acid-fast bacteria, like Mycobacterium tuberculosis, retain the primary stain, which is carbol fuchsin, and appear red or pink against the blue background of the surrounding tissue cells.