Final answer:
The correct answer to the question is 'c) Visibility and identification' as green is a color commonly associated with safety due to its high visibility, which is crucial for visibility in various lighting conditions.
Step-by-step explanation:
The question addresses the choice of color for the ISO considering its association with safety organizations. Particularly, green is mentioned as a good color due to its high visibility and identification properties, especially in safety contexts. For instance, green and orange are often used on caution signs or uniforms of emergency workers. When vests are equipped with bright-colored lights and reflective arms, they are significantly more visible in different light conditions which is crucial for safety at night or in low-light environments. Therefore, the correct answer to fill in the blank is 'c) Visibility and identification'.