Why do water bottle caps have different colours like blue, white & yellow?
General physician Dr Aniket Mule said the colour of a bottle cap often indicates the type of water. White cap means RO or machine-filtered water, while blue cap indicates mineral-rich spring water. Green is for flavoured water, red for electrolyte-enhanced water, and Yellow for vitamin-enriched water. Clear caps represent natural spring or distilled water, and black caps indicate alkaline water.