The article delves into the importance of understanding the various colors used to categorize hydrogen and their impact on fleet operations and environmental goals. While hydrogen is an abundant element, its extraction from sources like water, methane, and oil involves different production methods with varying environmental implications. Green hydrogen, obtained through electrolysis powered by renewable energy sources, is highlighted for its zero emissions during production. Other colors such as yellow, grey, blue, turquoise, pink, brown, black, and white hydrogen are explained based on their production methods and environmental footprints. The article emphasizes the significance of carbon intensity values in assessing the true environmental impact of hydrogen production methods, especially for initiatives related to ESG goals and investor attractiveness. By categorizing hydrogen using color codes and considering carbon scores, stakeholders in the industry can make informed decisions to align with sustainability objectives. Furthermore, the discussion extends to the role of impurities in hydrogen, particularly in distinguishing between fuel specifications for fuel cells and hydrogen engines. The need for pure fuel in fuel cells, compared to hydrogen engines, is highlighted to ensure optimal performance. Government initiatives, such as the U.S. Department of Energy's National Clean Hydrogen Strategy, focus on carbon intensity values rather than color codes to drive clean hydrogen production. This strategic shift aims to streamline industry standards and provide a clearer framework for stakeholders to navigate the evolving landscape of hydrogen technologies and sustainability practices.