Thursday, May 8, 2014

Disappointing Color Fading

I use all kind of colorants to soap, some natural some synthetic.  Sometimes I run into situations where color morphs into an undesirable hue, or fades during the curing process.  It's very common that natural colorants fade in time because most of them are light sensitive.  I can make a batch of soap with the most vibrant beautiful colors just to find them unsellable at the end.  Let's see the runner ups.

Here is the soap made with Spirulina (a type of algae).  Spirulina is a deep green powder that smells fishy and when it's added into soap and then forced gel it produces this vibrant intense leafy green color.  Then a few weeks later that vibrant leafy green turned into yellowish olive green.

Here's another one using natural colorant, Gromwell root infused 72% olive oil soap.  Gromwell root is widely used in Asia mainly for herbal medicine.  It is infused in oil and butters to make slave or balms to treat various skin conditions.  It can also be used as fabric dye for purple color.  Soap color made with Gromwell root infusion can range from blue purple to plum purple depending on the harvest.  Again, the beautiful intense color didn't last...

Now this final one surprised me.  I've used this specific colorant before and never have it fade on me in such a short period of time!  It turned to barely anything in just 2 days!  Yellow #5 lake is a strong yellow dye, it's synthetic, not natural.  I suspect the fragrance I used for this batch has something to do with the yellow disappearing.
What colorants have you tried that don't last?


  1. Thanks for sharing, Emily. Annatto seed produces a beautiful yellow but completely disappears after more than 6 - 8 months. I am currently using moringa powder. It creates a gorgeous avocado color. The color does not morph but i suspect it fades. My soaps are still a month old.

  2. Turmeric fades unless mixed with annatto. Although I do an oil infusion for my colors.

  3. I used spinach powder...and it browned a few months later like your spirulina did.

    It actually took me a few looks to notice the faded yellow, I think because the pink is so beautiful it more than makes up for that...but I know how frustrating that can be.

  4. This was a good one, Em! Thanks for sharing! The only one I had literally fade to NOTHING was the purple pigment powder from WSP. I knew better than to use it in cold process, but boy howdy, it literally faded to CLEAR in melt and pour and it wasn't exposed to the sun at all. Total disappointment. I don't know what I'm going to use it for because it turned grey in my cream soap too! It's the high PH I just know it, but for melt and pour too? I mean....really!? ha ha

  5. I used chlorella for colouring almost the same time you used that spirulina. Chlorella changed too, but not that much. That Gromwell root purple change is huge too, but colour is still beautiful. I didn't know, that synthetic colours can fade too, I thought they were "sure".

  6. I know this is probably a little late, but I suspect I know what happened. The coloring agent in spirulina is chlorophyl. Chlorophyl is very, very sensitive to UV light (sunlight), gromwell is too. Exposure to sunlight destroys these colors. A totally awesome way of figuring out if your natural colorants will fade is to pick up a book on natural dying. Look at how "lightfast" something is, and it will often give you a good idea if sunlight will destroy your color or not. Looking at the dying process will also tell you if high pH will detroy your color. For example, something that needs an acid bath for a certain shade will look like crud in soap.

    Synthetic colors can totally fade if you mix them with something they don't like. Did you use any sort of organic food product in your soap? Tartrazine (yellow #5 lake) fades a lot if exposed to vitamin C. It also can fade or morph if your scent has too much sulfur dioxide in it. Other issues with fading and morphing can just be due to cold process, that high pH just beats on so many things.

    I love your blog by the way; you make the most gorgeos soap and cosmetics. I'm not so artistically skilled, so I'm always jealous.

    1. I didn't know that about yellow #5 lake! Great info, thanks!

  7. Hi Emily, I' m Sheela fr Malaysia.i love ur soaps. Well I hv just started soaping. Hope to u can give some feed back about my soap one day. Tq

  8. Hi :)
    Lake 5 is a dye. Best results for dyes are to mix the color in right with the oils, before adding the lye. It really is a strong colour
    Love the design!

  9. For green i use Wheatgrass powder,carrot juice for yellow,infusion of paprika for pink.There are colors who don't change in time

  10. I had the same results with spirulina, except for some reason it held it's color better as long as it didn't touch the other bars of soap while curing. Anywhere that two bars touched turned the same yellowy blah green after just a few days. Wheatgrass powder held up over time better for me, but did still fade a bit, especially when it was exposed to sunlight for any amount of time. I have found that adding a bit of vitamin e oil (a natural preservative) to my oils helps to maintain the colors of any natural additives I add. Thanks for the post!