***IMPORTANT NOTICE REGARDING THE COLOR OF YOUR C E FERULIC: Initially, the C E Ferulic is a transparent liquid when freshly manufactured. However, prolonged exposure to heat, light, and air causes it to transform into a yellow hue. It is important to note that this change in color does not indicate that the product is old or expired, unless it becomes significantly dark. Even when the serum turns yellow or even orange due to oxidation of the vitamin C and Ferulic acid, it can still be safely used. To maintain its clarity for as long as possible, we recommend storing the product in the refrigerator, as is advised for all vitamin C skincare items. This will help preserve its clarity and freshness, allowing for an extended period of usability. Rest assured that the majority of our Ferulic products are delivered to you completely clear, as they do not stay on our shelves for long.