I watched several girls and guys use way over the recommended amount of mica
Are you sure about that? I follow quite a few YouTube soap makers and what you see can be very misleading...from the size of the batch to the amounts of ingredients and additives. One of the things I struggled with in the beginning was stick blending. It took me a bit to understand that quite a few of them were making much larger batches of soap than I was...a one to two pound difference can have quite an impact. As does what oils and butters they are using as some recipes can be slower to trace than others. And a lot of times they are using the stick blender like a spoon...they don't actually have it turned on.
Then there are a lot of different teaspoons and tablespoons out there and what you see on camera can be misleading. What you might think is a teaspoon is actually only a half a teaspoon or even a quarter a teaspoon, or a tablespoon is actually half a tablespoon. It's even more misleading if the colorant has been dispersed in water or oil (or other liquid medium) at a rate of 1 teaspoon of colorant to 1 tablespoon of oil/water.
And not all colorants are the same. You have Micas, Clays, Pigments, Oxides and Natural Powders. I remember the first time I used Pigments/Oxides instead of Micas...what a mess my soap was. You would have thought a Fourth of July celebration had vomited in my shower...I had red, white and blue running everywhere! When I made the soap again, I only used about a third as much...got the same colors, but without the pudding and bleeding.
And another thing...black oxide and titanium dioxide are your friends when it comes to darkening and brightening your colors.