Guide to using colours (Part 1)

Each week we will be looking at colouring soap and this week we start with cold process.

One of our most frequently asked questions is what colours to use for certain products.

So here is a quick guide to using colourants by product;

There is no definitive usage rate for colours in cosmetic products. How much you add depends on a number of factors, including the type of colourant and the recipe used. The depth of colour will vary with the amount added. Start off with a few drops and build up to the required colour, remember to keep a note of how much you used ready for next time.

Colouring Cold Process Soap

The main thing to remember when choosing a suitable colour for cold process soap is that it needs to be alkali stable, sodium hydroxide can cause a reaction that changes the final colour; blues can turn pink for example. So before you make a large batch always test your planned colourants in a small batch

Mineral and Organic pigments have high tolerance to alkali (except for Manganese violet powder) and generally they give gentle earthy colours to soap. Although Oxides are synthetically produced, they are “nature identical”, meaning they have the same molecular makeup as the once mined pigment from the earth.

  • As ultramarines and oxides start as a powder, they need to be suspended in water before adding them to your soap. If you want to maintain the same colour through the batches you will need to ensure you are mixing to the same ratio each time and keep a note (ie 5g of powder in 50g of water).

 

  • Some types of pigments (known as insoluble pigments) are NOT water soluble so will need mixing with warm oils. Add to melted coconut/palm oil and whisk in very thoroughly to avoid any ‘spotting’.

 

  • Water Dispersible pigments are dispersions of organic insoluble pigments created by adding them to a liquid base together with an emulsifier. They disperse in water and add colour by ‘coating’ the molecules of the products they are added to. Organic water dispersible pigments are very alkali tolerant and can be used successfully in CP soaps.

 

  • You can add the colour at any time once all the base ingredients have been added, before or at trace. With ALL colours/pigments, the depth of colour will vary with the amount added. Ultramarine violet and pink can appear grey in cold process soap, just add more colour and mix well, and use a stick blender if needed to help disperse the colour. Keep colours subtle to avoid bleeding of colour into the lather when using the soaps.

Water Soluble Dyes have small particle size and lend their colour to products by solublising. Some dyes are less tolerant of extreme pH environments than others which mean that not all are suitable for use in alkali products such as CP soaps. Dyes are synthetic and are not considered natural or “nature identical”.

  • If bought in powdered form it will need to be diluted in water, to make a concentrate use a maximum of 5% by weight in 95% water. Dyes should always be used sparingly and never added to any dry toiletries in their powdered form.

When diluted in water, dyes often appear a different colour from that of their concentrated liquid or powdered forms.

 

  • You can add the colour at any time once all the base ingredients have been added, before or at trace. With ALL colours/pigments, the depth of colour will vary with the amount added.

 

  • Dyes can bleed into layers of the soap, sometimes this can be the look you want, but not if you want a nice crisp line of colour.

 

  • Some of the names can be confusing; labels such as D&C mean it’s suitable for drugs and cosmetics, FD&C means it can also be used in food.

Natural Dyes are similar to synthetic dyes in that they have small particle size and lend their colour to products by solublising, but they are derived from natural sources as is evident from many of their descriptions. Some dyes are less tolerant of extreme pH environments than others which means not all are suitable for use in alkali products such as CP soaps

  • Natural Dyes can come in powdered, granular or liquid form. When dilute or further diluted in water, dyes often appear a different colour from that of their concentrated liquid or powdered/granular form. Dyes should always be used sparingly and never added to any dry toiletries in their powdered/granular form.

 

  • You can add the colour at any time once all the base ingredients have been added, before or at trace. With ALL colours/pigments, the depth of colour will vary with the amount added.

 

  • Dyes tend to bleed into layers of the soap, sometimes this can be the look you want, but not if you want a nice crisp line of colour.

 

  • Advise testing before use in C.P. soaps.

 

Natural Colours (Spices & Botanicals)

Dried botanicals are a great way to decorate your soaps, along with adding decoration they can be used to give a natural colour to soaps. If ground to a fine powder mix into a paste with a little oil before adding to soap at trace, alternatively remove a small amount of soap base at light trace, mix in the powder and then return it to the pot and stir briskly. If using leaves, roots or larger pieces it’s usual to steep the cut or ground root in warm oils until the oils takes on the colour, then strain the particles from the oils and make your soaps with the coloured oils

  • Alkanet root. As far as herbs go this is one of the most sought after for its colouring properties. It’s usual to steep the cut or ground root in warm oils until the oils takes on the colour, then strain the particles from the oils and make your soaps with the coloured oils. The steeped oil is a rich dark red but will turn lavender purple to blue in soap.

 

  • Ground cinnamon can be used for its colouring and decorative purposes on soaps and cosmetics. When added to soap, cinnamon gives a warm light brown shade with speckles and gives a pleasant spicy aroma. It is mildly abrasive to the skin, has gentle antiseptic properties, and adds longevity and character to the lather. Mix into a paste with a little oil before adding to soap at trace or remove a small amount of soap base at light trace, mix in the powder and then return it to the pot and stir briskly.

 

  • Cocoa powder is a wonderfully fragrant product that makes an excellent addition to soaps and many toiletries, both for its warm brown colour and its curative properties. Mix into a paste with a little oil before adding to soap at trace. Please note, using too much may overpower your chosen scent and some people are allergic to cocoa.

 

  • Curry powder has a pleasant sweet and aromatic fragrance and can be used as a natural colourant in soaps giving a gentle peachy yellow. Mix into a paste with a little oil before adding to soap at trace or remove a small amount of soap base at light trace, mix in the powder and then return it to the pot and stir briskly.

 

  • Seaweed & Algae. Kelp, bladder wrack and spirulina, as well as being used for their concentration of minerals and nutrients can also add colour and texture. Kelp and bladder wrack tint a pale green-grey and spirulina is bluer. All have a distinct smell! Luckily the smell will disperse within a few weeks.

 

  • Paprika. From blusher to eye shadow, paprika has been making women look great for decades. Its deep red powder produces a salmon peach tint to soap with russet speckles. Too much can be abrasive.

 

  • Turmeric has been long used in Ayurveda and Chinese medicine as an anti-inflammatory agent, produces a golden yellow-orange colour in CP soap.

 

Minerals and Clays as well as imparting their own properties, can be used to colour cold process soaps, ranging from delicate pastel shades through to deeper earthy hues.

 

Coloured Micas are fine pigment-coated mica powders which are widely used in many cosmetic applications as they add colour with a fine glittery sheen. They are almost all very alkali tolerant making them ideal for use in CP soaps.

  • Mica colours soap by suspension of their particles. If you are making a single coloured soap, you can add mica to the oils before pouring in the lye solution.

 

  • You can also add to traced soap, but adding it to the oils allows you to have enough time to mix in without your soap getting too thick. Mica doesn’t clump too badly and can usually be stirred in by hand when added at a light trace. Using of a stick blender helps to disperse the mica.

 

  • Mica is considered natural but the type of colour used would determine if it is synthetic or natural. Dye coloured mica is synthetic, pigment coloured mica would be synthetic but “nature identical”, meaning they have the same molecular makeup as the once mined pigment from the earth.

 

Coated Mica Pigments differ from regular mica in that their coating allows the mica to freely suspend in water, unlike regular mica which tends to float on top and then cling to surfaces such as the bath itself or your skin.

To view the colours and application chart, click here

5 thoughts on “Guide to using colours (Part 1)

  1. I am a beginner and producing as many failures as successes! What are the best conditions for drying? Should the container be airtight and should I have a rack to allow air to circulate or just put on kitchen roll as I have been doing? Also, if I add fragrances and colours, should I use correspondingly less water?

    1. Hi Miranda, thanks for your question. Yes soap making can be like that, lots of trial and error, but keep at it and you’ll start to learn what works and what doesn’t. With regards to drying, a rack in a pantry would be best as you want as much air circulating around it as possible, and the air temperature needs to be not too hot or too cold. You shouldn’t have to use less water either if you’re using fragrance & colour. If you’re stuck for any recipes we have lots here on the blog and on our main website too that you might find helpful 🙂 https://www.thesoapkitchen.co.uk/recipes-and-guides/

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