Unwanted color development - eyebrow color formulation
I am trying to identify the source of unwanted color development. The formulation is a liquid eyebrow pen on the market. I am convinced that this is not a one-off incident, as the product has received many similar complaints online about the product leaving a greencast on the skin. (google green eyebrow pen)
I contacted the brand, but was informed that the color change was because of how it was stored at the major retailer where I bought the pen.
I don’t have access to a microscope so I am unsure whether it is microbial growth. Perhaps the formula needs a better biocide? I’m also fairly confident that it is in a PP container. Below is the ingredient list (sorry I don’t have percentages):
G2014172INGREDIENTS: AQUA / WATER / EAUALCOHOLGLYCERINPVPPEG/PPG-14/4 DIMETHICONEPROPYLENE GLYCOLPENTAERYTHRITYL TETRA-DI-T-BUTYL HYDROXYHYDROCINNAMATETRIISOPROPANOLAMINE[+/- MAY CONTAIN / PEUT CONTENIRCI 16035 / RED 40CI 42090 / BLUE 1CI 19140 / YELLOW 5] F.I.L. D217393/1
I am asking out of a place of wanting to learn from others mistakes and not repeat the same mistake when I formulate.