Minerals, pigments and optical ingredients

CI 42090 · blue colour

A dramatic sculpted brilliant-blue wave rises behind a clean ivory cosmetic slice.
About this illustration
The blue material tideThis illustrated blue tide makes one part of a colour palette visible. CI 42090 can join other colourants, so its blue identity need not match the finished bar’s shade.

A blue ingredient need not make a blue bar. CI 42090 can join other colours in a carefully balanced mixture, giving a familiar-looking solid a colour story that is more interesting than the finished shade suggests. The number is the useful anchor behind several different names.

Name on the ingredient listCI 42090

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A quick answer

CI 42090 identifies a synthetic blue colour family associated with Acid Blue 9 and FD&C Blue 1, also known as Brilliant Blue FCF. It is used to colour cosmetics and has both straight-dye and lake preparations in supplier and regulatory systems. The exact supplied form matters. In a solid cosmetic, its visual job is separate from cleansing, conditioning or scent; a blue component can also help create a different final shade when combined with other colourants.

A blue note inside another colour

A current solid shampoo label lists CI 42090 beside a yellow and a red colourant. That is a useful real-world example of why an ingredient's colour name need not match the product's finished appearance. The maker is working with a palette, not displaying each colour separately.

When you see a numerical colour list, imagine the components of the shade rather than a row of competing colours. Their proportions and the background of the formula determine what your eye sees. A blue ingredient can be a contributor to balance, depth or a mixed hue.

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Several names, one useful anchor

Acid Blue 9, FD&C Blue 1 and Brilliant Blue FCF are names you may encounter in the same colour conversation. CI 42090 supplies a numerical reference that helps connect those naming systems. The numbers do not describe a concentration or tell you how blue a finished product will look.

This is especially useful across markets and languages. A shade's marketing name may change completely, while a technical colour identity remains traceable. The code is less poetic than an ocean-inspired product name, but it is often the more helpful part when you want to know what material is involved.

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A large ingredient-code card is enlarged through an illustrated paper magnifier, keeping the full CI 42090 name together.
CI 42090
The complete code survivesKeep the letters and every digit: CI 42090. The code helps you follow a colour identity across different product names and languages; it is not a concentration or a promise about the finished shade.Visual references: CI42090 ingredient identity
An open ingredient-list fold reveals a central colour-code card beside two native name cards for Acid Blue 9 and FD&C Blue 1.
CI 42090Acid Blue 9FD&C Blue 1
From code to identityCI 42090 connects several naming systems. Acid Blue 9 and FD&C Blue 1 are useful names to recognise alongside it. Exact supplier preparation still needs its own details; a shared code does not establish whether the supplied material is a straight dye or lake.Visual references: CI42090 ingredient identity

A manufactured colour, not a blue botanical

CI 42090 belongs to the triphenylmethane dye family. It is a manufactured colour rather than an extract of a blue flower or a mineral powder selected for its natural shade. The preparation is designed around a particular colour identity.

That difference matters when interpreting the appearance of a botanical-looking product. A plant oil or extract can be present for one reason while a separate colourant creates or adjusts the visual shade. Knowing that lets each ingredient keep its own story, without asking the colour of the bar to prove the origin of everything inside it.

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A colour can be prepared in different forms

A straight dye and a lake are different preparations. A lake attaches a colour to a suitable substrate so it can be handled as a pigment. FDA's Blue 1 listing distinguishes the straight colour from its aluminium-lake preparation, which is a useful reminder that the exact form is part of formulation.

The bare CI code does not identify every detail of a supplier grade. The important insight is the difference between colour identity and physical preparation. The maker chooses both, so the colour can fit the particular medium and format.

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Appearance is a legitimate part of design

Colour can help a person recognise a favourite solid among several similar shapes. It can also support the product's visual character. Those are practical and aesthetic jobs, separate from the surfactants that wash or the materials that create glide.

CI 42090 therefore does not need a care claim to have a reason for being present. It belongs to the visible design. Recognising that makes an ingredient list easier to read: not every component has to be the main active part of the product to contribute something useful.

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A uniform pale blue solid is opened by external cream paper layers, while a separate blue paper reference identifies the colour contribution.
Colour contribution · paper referenceSurrounding formula · metaphorFinished solid · illustration
Colour within a solidA colour belongs within a much larger formula. This external paper model separates the idea of colour from the surrounding materials without showing literal ingredient compartments, quantities or a colour-mixing recipe.

Use the code to understand the palette

For everyday choosing, look at the finished shade and the product's intended use. A blue number in the list is a clue to construction, not an instruction to expect blue hair, blue skin or a particular foam colour. Those results would require a product deliberately designed and described for them.

The enjoyable discovery is the palette behind the object. A small solid can contain a carefully chosen visual mixture, with the same thought given to its colour as to its shape. CI 42090 is one of the anchors that lets you follow that design.

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A blue cut-paper colour reference for CI 42090 is separated from a fine ultramarine-blue powder example labelled CI 77007.
CI 42090 · colour referenceCI 77007 · powder example
Blue beside ultramarineSimilar blue words can point to different materials. CI 42090 and CI 77007 are separate identities. The left paper is a colour reference because its exact dye or lake preparation is unspecified; the right illustrates documented ultramarine powder form.Visual references: Ultramarine Blue
Three separate reading scenes connect a blue bar’s visible shade, the exact CI 42090 identity and its separately described scent.
Look at the shadeFollow CI 42090Read the scent description
Colour is not scentThe shade, the colour ingredient and the fragrance description tell different stories. A blue appearance does not identify an essential oil, prove a botanical origin or establish a toning effect. Use the product’s own description for those details.

Questions you might have

Does the code mean the product is blue?

It identifies a blue colour ingredient, but the finished shade depends on its partners and the formula's background. A current solid label uses it with other colourants. The list describes the palette, while a product image or swatch shows the combined appearance. Keeping those two levels separate makes colour codes much less puzzling.

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Is it the same as ultramarine blue?

No. CI 42090 is associated with Acid Blue 9/Blue 1 chemistry, while ultramarines have a different inorganic pigment identity, commonly CI77007. Both can contribute blue, but shared colour does not mean shared composition or formulation behaviour. The CI number is useful precisely because it keeps those materials distinct.

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Does a blue shampoo automatically tone the hair?

No. A colour ingredient in a shampoo can colour the product itself. Toning is a purpose of a specifically designed finished formula, with its own claims and directions. Follow that product description rather than assigning a colour-correction result simply because a blue code appears among the ingredients.

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One useful thought

CI 42090 is a small doorway into a larger palette. Its blue identity, alternative names and possible preparations explain the material; the blend explains the final shade. Once those pieces are separated, a numerical colour entry becomes a useful design clue instead of an interruption in the ingredient story.

Sources

References and further reading
  1. CI 42090 – IngredientCOSMILE Europe
  2. 21 CFR74.2101: FD&C Blue No.1US Food and Drug Administration / eCFR
  3. Champú Sólido Hemp: IngredientsValquer