Cosmetics Formulation Development

I would like to inquire about the production of cream for research. that if you want to produce a placebo with a product with active ingredients, which here is Calendula officinalis extract 0.9% where all other ingredients are the same. Will be able to produce the cream that has the same physical characteristics. Without the user being able to distinguish color and smell? thank you

Hello, it can be done, but it's not easy, you need to see Calendula officinalis extract 0.9% how does it affect the physical effect of the formula? Usually, substances extracted from Calendula usually has a color (yellow or red because it has a Lutein group), so this will overload the formula. How to make Placebo look the same May be a dark color so that it can't be seen that Which one has Lutein's color?