There are various liquid dyes you can buy. Not all of them are suitable, make sure you buy soap safe and skin safe liquid colors.
You will only need a few drops, so color your soap drop by drop.
A large benefit of liquid dyes is that they are very easy to work with, no mess.
They will leave the soap translucent unless you use a lot.
Almost all of these liquid dyes will bleed when used in a multi color soap,
so do not use liquid dyes for anything but single color soaps, or make very sure you buy non-bleeding liquid colors and test those by leaving them for a month or two to make sure they really do not bleed.
Most liquid dyes will fade if exposed to too much UV light.
Use liquid dyes if you are looking for matte or translucent colors.
There are various micas you can buy. Not all of them are suitable, make sure you buy soap safe and skin safe mica.
Use mica if you're looking for a shiny/shimmering type of color. Not all mica is shiny but most are at least a bit. If you use mica in a white base the color will be more matte.
Premix your mica with a little alcohol or your scent oil to prevent clumping. Unless you like the look of a few colored clumps, I've made a few soaps like that myself on purpose.
There are cruelty-free micas available, these are generally sold as 'synthetic mica'.
Besides coloring your entire soap with mica, you can also mix some with alcohol and paint your soaps. This will rub off in the packaging and with the first use though, you can carefully 'seal' your painting by painting a layer of clear base over it to prevent this.
You *can* do translucent soap with mica with some practice, but if you're doing a single color soap I would prefer liquid color for that as it's easier and also not shimmery.
A lot of soap shops carry colorblock systems for soap coloring. These systems may be slightly expensive but they are generally very easy to work with, don't bleed and some are translucent, making these a good substitute for liquid dyes in multicolor soaps.
The stained glass soap on the cover photo was done with Zenicolor colorblock system, plus activated charcoal for the black.
- Activated charcoal, for a solid, slightly shiny black (when used in clear base). Premix this with a bit of alcohol to prevent clumps. The finest charcoal is made out of coconut, this will give a shiny finish. Other kinds are more grainy. Don't buy the kind used for teeth whitening unless it has no other additives.
- Various clays, as sold by soap shops. These generally give very subtle colors, as you can only use a little in melt and pour.
- Turmeric powder. This color may fade over time though. If you use too much turmeric is known to stain the lather, skin, fabric and even the sink itself.
- Used very dry coffee grounds. Note: these *might* spoil at a later date anyway. YMMV. Also you cannot use instant coffee.
- Oxides, like titanium dioxide. Basically, white soap base = clear soap base + titanium dioxide! However titanium dioxide lessens lather, so use sparingly.
- Other natural options that are NOT safe for melt and pour are those made out of herbs, fruit etc. as those will spoil in melt and pour (see About Additives). So no beetroot powder, carrot powder or anything like that, aside from turmeric.
- Only use liquid colors for 1 color soaps. If you want multiple colors always use mica, as liquid colors will bleed.
- For strong colors use a clear base. A white base + color will give you pastels.
- Only use skin safe and soap safe coloring. Keep in mind that edible does NOT mean skin safe! The manufacturer has to state it's skin safe, specifically.
- If using mica or other powdered type of coloring, premix this with a little alcohol or your scent oil to prevent clumping.
- Keep any added liquids, butters, powders or oils (including scent oils and liquid color, no need to include alcohol) combined to max 1 flat teaspoon per pound/500g of base.