Colour Cosmetics 101: Mica, Iron Oxides, Lakes and the Rules Behind Them

Colour is the most fun part of makeup, and the most rule-bound. A pigment that's perfectly legal in a body butter might be off-limits in a lip balm or an eyeliner. Before you start swatching, here's your map.

The colour families

• Mineral pigments: Red, Yellow and Black Iron Oxides (mix them for every skin tone), Titanium Dioxide for white and opacity, Ultramarine Blue, Chromium Oxide Green and Manganese Violet.
• Organic dyes and lakes: bright, saturated synthetic colours like Red 7 Lake. A "lake" is a dye fixed onto a mineral base so it disperses instead of dissolving.
• Pearls and shimmers: Mica on its own, or coated with titanium dioxide or iron oxides for glow, like Silver Mica Pearl. Synthetic sparkle alternatives include Calcium Aluminum Borosilicate flakes.
• Natural colours: Carmine, a deep red.

Rule 1: every colour has a "where"

In the US, only FDA-approved colour additives may be used in cosmetics, and each has permitted uses: the eye area, general use including lipstick, or external use only. Some also have concentration limits (FDA colour additive table). Synthetic iron oxides, for example, are permitted for cosmetics generally, including the eye area (21 CFR 73.2250). As our lip care post explained, "external use only" colours can't go on lips.

In the EU, colourants must appear in Annex IV of the Cosmetics Regulation, which also sets conditions such as "not to be used in eye products", "not to be used in products applied on mucous membranes" or "rinse-off products only" (Annex IV, UK retained copy). Iron oxides and carmine carry no field-of-application restriction there.

The practical habit: before you put a pigment in an eye or lip product, check its permitted uses for every market you'll sell in. Each pigment's dictionary entry flags this as a regulatory check (see red iron oxide).

Rule 2: carmine isn't vegan

Carmine's beautiful red comes from carminic acid, extracted from the female cochineal insect (Dactylopius coccus) (Reyes-Pérez et al., Molecules, 2024). In the US it's exempt from batch certification but must be declared on the label (21 CFR 73.2087). For a vegan red, use red iron oxides or a permitted lake.

Rule 3: ask where your mica comes from

Mica gives makeup its glow, but its supply chain has a dark side. A 2016 investigation by the research group SOMO found at least 20,000 children working in mica mines in Jharkhand and Bihar, with that mica reaching cosmetics supply chains (SOMO). A Thomson Reuters Foundation investigation reported child deaths in illegal mines being covered up (Thomson Reuters Foundation via Eco-Business). These reports are from a few years ago, but the issue remains a key sourcing concern.

What you can do: ask every supplier (including us) for mica origin and traceability documentation, and consider synthetic shimmer alternatives where you can't verify the source.

Formulating tips for beginners

• Disperse pigments well. Grind them into a little oil (or glycerin for water-based formulas) before adding to the batch, or you'll get streaks and specks.
• Start tiny. Iron oxides are strong, so add them in small amounts and build up.
• Test on several skin tones for complexion products.
• Use cosmetic-grade pigments only, never craft pigments or food colourings. They may not be permitted, and they may not be pure.

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