Before you embark on selecting colors for your own handmade cosmetics a knowledge base on the fundamentals of color theory, color chemistry and color properties is helpful and important.
When evaluating a color for your cosmetics there are three key elements that need to be considered.
Color Additives fall into one of two broad categories: Dyes and Pigments
Generally in cosmetics, the term solubility relates to water solubility. The majority of colors used in decorative cosmetics are pigments. All the colors we sell at DIY cosmetics will fall into the pigment category.
Inorganic Pigments: The range of inorganic pigments used in cosmetics is made up of several different chemical types. In general, inorganic pigments are duller in color than their brighter organic counterparts. They are far superior though in the stability to heat and light. They can react in extreme conditions of pH. For example Ultramarines can react with acids and produce hydrogen sulphide as a by-product. It is the inorganic pigments that we most use in cosmetics subject to their purity levels of heavy metals.
Iron Oxides: These inorganic pigments are used in all types of cosmetics and have three basic shades: black, yellow and red. By blending these three oxides in the right proportions you can produce an array of browns, tans, and umbers for liquid foundations, face powders, and blushers. By careful blending an array of natural looking flesh tones may be produced.
Chromium Dioxides: The Chromium dioxides are used for most categories of cosmetic preparations but are not permitted for use in lip products in the USA. Colors range from dull olive green, to a blue green, or bright green.
Ultramarines: Ultramarines vary in shade from bright blue to violet, pink and even green. Ultramarine blue is not permitted in lip products in the USA.
Manganese Violet: This brightly colored inorganic pigment is purple colored.
Iron Blue: This very deep intense dark blue pigment is widely used in all cosmetic applications. It is not permitted in lip products in the USA
White Pigments: White pigments are widely used in all cosmetics, they have extremely good covering power and are almost totally inert in addition to being extremely stable to heat and light. Titanium Dioxide and Zinc Oxide are the most commonly used in cosmetics.
Mica: Chemically Mica is potassium aluminum silicate dihydrate. It is mined as the ore muscovite and occurs in multi-layered bright translucent sheets. Cosmetic Mica is refined and ground to particle sizes from 150µm or less before use. Mica imparts a natural translucence to face powders and powder blushers when used at levels up to 40%.
Pealescent Pearls : Plate like crystals that have a highly refractive index. The pearlescent effect is obtained as a result of individual plates lining up and acting like tiny mirrors. There are various types of materials used in cosmetics to produce this effect.
Organic Pearls: Organic cosmetic pearls produce a bright silver effect and were only available from fish scales. Although they are still available, but in short supply organic pearls are very expensive and have almost exclusively been replaced by synthetic organic pearls.
Inorganic Pearls: Bismuth Oxychloride produces a silver grey pearlescent effect. The effect is based on the crystal size. Smaller crystal size gives an opaque smooth luster and larger crystal size gives a more brilliant sparkling effect.
Silver Pearls: Titanium is used to coat platelets of mica. Titanium can exist in two crystal forms, either anatase or rutile. The rutile crystals give a particularly brilliant pearl effect, caused by their higher refractive index.
Colored Interference pearls: In addition to ultra-thin layers of titanium dioxide being deposited onto mica, colored pigments can also be laminated with this interference film. This produces a two color effect caused by the light rays being reflected and refracted or transmitted at the different pigment layers.
Colored pigmented pearls: Colored pearls consist of layers of titanium coated mica, with an additional color and luster effect which is more pure than can be achieved by simply mixing pigment with silvery pearls.
Organic Pigments: There are three types of organic pigments: Lakes, toners and true pigments.
· Lakes are pigments made by absorbing the dye on a substrate such as alumina hydrate. There is no chemical bond between the dye and the substrate. The dye takes on the insoluble nature of the substrate. Based on the absorptive powers of the substrate, the amount of dye in the lake may range from 12-40%.
· Toners are more resistant to light and heat but extreme pH can change the shade.
· True pigments are the most stable but they are relatively uncommon.
GLOSSARY OF TERMS AND INGREDIENTS
Binders: Pressed face powder and eye shadow are extremely popular because they can be easily carried and applied. In order for a free flowing powder to be pressed into cosmetic containers a liquid binder has first to be uniformly dispersed through it.
Certified Lot Number: This is the identifying number assigned to each batch of colorant by the FDA when a manufacturing company’s submitted batch is certified. It is unique to that color and that batch.
Hue: The hue or shade of color is described by using the Color Index (CI) terminology. It is a method which was developed to standardize the verbal description of colors.
Safety: All the certified dyes listed for use in the US have been tested at least three times. “Safe” is determined by law as “convincing evidence that establishes with reasonable certainty that no harm will result from the intended use of the color additive.
The Color Index (CI): This is the best known reference book on color, edited jointly by the Society of Dyers and Colorists, and the American Association of Textile Chemists and Colorists. No matter what language one speaks if the CI number is known, the chemical, structure, and physical properties of the colorant is available.
The Code of Federal Regulations (CFR): The CFR is the codification of the rules published in the Federal Register by the Executive branch and the agencies of the U.S. Federal Government. It is updated annually.
FD & C Colors: For use in food, drug and cosmetics.
D&C Colors: For use in drugs and cosmetics.
Ext. D&C Colors: Colors for use in externally applied drugs and cosmetics which do not come in contact with mucous membranes.
For the most part the inorganic pigments, pearlescent pigments and Lakes are what we will use and sell at DIY Cosmetics. They are generally the safest and most approved colors for use in eye shadows, powders, blushes, mascara, and eyeliner. It is important that the pigments used are specially produced for cosmetics and purified with no heavy metals.
Dyes: Colorants which are soluble in vehicles such as water, alcohol, glycerin or oils.
Natural Dyes: Widely used in foodstuffs there is no restriction on the use of natural dye in cosmetics apart from purity considerations. In general natural dyes are not resistant to heat, light, and pH stability. This makes them much inferior to their synthetic counterparts. They should be thoroughly tested in finished products. In some instances natural dyes exhibit strong odors. DIY Cosmetics Sells a line of these natural colorant in liquid form sourced from plants and flowers.
Pigments: Colorants which are insoluble in the vehicle in which they are used.
Acid Dyes: All of the water soluble dyes are classified chemically as acid dyes. Acid dyes are usually the sodium salts of sulfonated or caboxylated dye molecules.
Solvent Dyes: The oil soluble or non-polar dyes are those which have no salt forming groups on the dye molecule. They will dissolve in hydrocarbons, oils, waxes and aromatic solvents.
Pure Dye: This is the amount of dye actually contained in the certified colorant, exclusive of inorganic salts, moisture, side reaction products, or un-reacted intermediates.
THE EFFECTS OF PARTICLE SIZE
Different effects can be achieved by the right choice of pigment and particle size. Small particles (less than 15 microns) create silky and satin effects and will opacify the mass. Larger sized particles (larger than 100 microns) create high luster effects, either sparkling or glittering, combined with high brilliance and transparency.
There are a few basic rules that we follow when formulating with pearl luster pigments.
COLOR EFFECT vs. PARTICLE SIZE
Particle Size 15 µm or less = low luster, good hiding power
Particle Size 2-25 µm = silky luster and strong hiding powder
Particle Size 10-60 µm = pearl luster with medium hiding power
Particle Size 10-125 µm = shimmering luster and low hiding power
Particle Size 20-150 µm = sparkling luster and transparent
Particle Size 45-500 µm = glittering luster and very transparent
It is worth noting that MICA pigments with a particle size over 150 µm are not permitted in cosmetics in the US.
This information about particle size will come in handy when it comes time to make up your own recipes. If you are making a transparent powder the less opacity the formulation has the better your pearlescent effect will be. In these transparent powders the amount of pigment if fairly low to the ratio of MICA and fillers.
Pearlescent Pigments should never be ground with a mortar and pestle. By grinding them you break or remove the metal oxide from the mica plates which will result in a loss of luster and change in color. Pearl pigments are easy to mix into other ingredients and can always be mixed in at the end.
Oxides and Lake Pigments do not have a lustrous effect and are difficult to blend. The conventional oxides are very difficult to get properly dispersed without high speed mixing equipment.