While editing one of the materials in question in a Shader Editor, create a node group by selecting the relevant nodes, and pressing Ctrl + G. In the example below, I only selected an RGB node, grouped it, and changed its name to COLOR. You can enter into a group by pressing Tab, that's what you're seeing the in the lower part of the screenshot:
Once you have that node group, you can simply copy it Ctrl + C, switch to other materials and paste Ctrl + V it into their material setup. You can also add this node group via Shift + A > Group > nodename.
Now, when you make changes to that node group, it'll be updated for all its copies in the file, even if they're different materials.