How can I change each individual colour in a texture?

I have this texture currently and I want to be able to change each individual colour seperately in materials. My end goal is to have a skin system which would allow the player to change how their dinosaur looks. However, I have no idea how to do it. I tried to do this setup and got this wierd result. Does anyone know how I could do it well?

right-click those color-values and change them to a parameter.

in your content explorer, right-click you material and make a material-instance. this is a specific configuration of parameters in your material. eg you can make a material instance w/red, another with blue. you can also set the values of these parameters via blueprint/c.

apply the material-instance to your dino instead of the base-material.

double-click the material-instance in the content-explorer or the on the mesh and it will open the parameter-list.