I'm just curious how everyone adds color to their icings and fondant, more specifically when using gels colors. I usually use a toothpick, but find it is difficult to measure how much I'm adding. For example, I need to color buttercream and fondant the same color. Usually I just add color as I go, hoping to eventually get to the right color. I'd like to be able to more accurately measure how much of each color goes into one so I can replicate it. Does anyone have any suggestions or tips?

I usually use a small spatula, because toothpicks don't transfer enough color at a time (this is for darker colors). But other than that, all I've ever been able to do is do it little by little and hope for the best. If I'm trying to match fondant and buttercream, I try to start with an all-shortening buttercream, so it will be as white as the fondant, otherwise the bc will always be a little yellower than the fondant. I'd love to hear of a way to do this a little more "scientifically".

I use a syringe, I read it here a while ago, plus that way you can measure, so you know what you made in case you need more, I use the syringes that Walgreens gives me when I fill my dd prescriptions. (they usually give me several when I only need one so I use the spares for this purpose)

I use tooth picks when i'm using Wilton but when I use Americolor I use the bottle itself but adding very little at a time for light colors.
IMO i don't think you can get an accurate measure for food coloring maybe between 2 batches of BC or 2 batches of Fondant yes, but definitely not between BC & F.
The problem with BC that it darkens 1-2 shades after drying, whereas fondant hardly changes color & at some points I find that it lightens

I just eyeball it..I have been doing this for so long you get to know what products does what and how much more you need or when to stop...That's what I love about Americolor....no messy toothpicks.