Tint only one texture and add it onto other textures

Hello!
I'm quite new to making shaders and I'm not very familiar with all the operations. I've been trying to make a simple shader that allows me to mix and match textures and add them to a material so they overlay. (I also just realized now I might run into a sorting issue, which is amazing that I haven't done that so far.) My current problem is that if I want to tint one of the textures, everything gets tinted and I don't know how to fix it.
This is what it looks like right now.

As you can see here, the "Eye Tint" applies the color to the whole material, when I only want it to apply to the eye texture.
Any help is appreciated!
Bonus question: How do I add those comment boxes? I can't find it anywhere!
I'm quite new to making shaders and I'm not very familiar with all the operations. I've been trying to make a simple shader that allows me to mix and match textures and add them to a material so they overlay. (I also just realized now I might run into a sorting issue, which is amazing that I haven't done that so far.) My current problem is that if I want to tint one of the textures, everything gets tinted and I don't know how to fix it.
This is what it looks like right now.

As you can see here, the "Eye Tint" applies the color to the whole material, when I only want it to apply to the eye texture.
Any help is appreciated!
Bonus question: How do I add those comment boxes? I can't find it anywhere!