Cream yellowing and skin staining from high concentration of Hi-Quercetin®

The yellowing of your cream and skin is caused by the high concentration (5%) of Hi-Quercetin® (Onion Extract) in your formula. As the staff mentioned, Hi-Quercetin® has a strong yellow color and can stain the skin, especially at higher percentages.

To fix this issue, you need to reduce the concentration of Hi-Quercetin® in your formula. For a day cream, it is recommended to use Hi-Quercetin® at a concentration of no more than 1%. Your current formula uses 5%, which is significantly higher.

Regarding your question about fixing the existing batch: It is generally not recommended to simply add ingredients to a finished cream to dilute a specific component. This can affect the stability, texture, and effectiveness of the product. The best way to resolve this is to create a new batch of cream using the adjusted formula with a lower concentration of Hi-Quercetin® (e.g., 1% or less).

The staff also suggested considering Vitamin B3 (Niacinamide) at 5% as a replacement or addition to help with skin strengthening and brightening, which could be an alternative if you reduce Hi-Quercetin®. However, you mentioned a previous sensitivity to B3, so you might want to test it carefully or consider other brightening ingredients if you choose to adjust the formula further.