For the purpose of establishing acceptance criteria for the cosmetic aspects of Molex’s components and assemblies, Molex issued a cosmetic specification. That document can be found here:
There are three different classes of surface for Molex products, each of which has its own requirements: Highly Decorative (Class A), Moderately Decorative (Class B), and Non Decorative (Class C), based on how visible the part or assembly is to end users or whether the part’s appearance is important to processing. These classes can be found in the datasheet drawing for Molex parts.
For example, when examining the 0039301060 six position header, there may be color variations due to the nylon is not dyed for the natural color. According to the datasheet, it listed “ PART CONFORMS TO CLASS “B” REQUIREMENTS OF COSMETIC SPECIFICATION PS-45499-002”, so the color variance is deemed acceptable if the color is recognizable.