According to Dr. Aniket Mule, a consultant in internal medicine at KIMS Hospitals, Thane, the color of a packaged water bottle’s cap often indicates the type of water it contains, although this is not a universal rule and lacks regulatory standards. He explains that black caps usually signify alkaline water, blue caps often denote spring water, and white caps typically represent filtered or processed water. Green caps are commonly used for flavored water, red caps for electrolyte-enhanced water, yellow for vitamin-enriched water, and clear caps may signify natural spring or distilled water. Dr. Mule emphasizes that for most healthy individuals, regular packaged or spring water is sufficient for daily hydration, and while specialty waters can be beneficial for those with specific needs like athletes, claims of major health benefits from alkaline or vitamin-enriched water are not strongly supported by scientific evidence. He advises consumers to always prioritize checking the bottle’s label for certifications, expiry dates, and storage conditions rather than relying solely on the cap color.