Hi . Thanks for the post,
I believe what you need is an instance of the material that you have already made. I am including a link to our tutorial page on material instances.
You can use this to create an instance of your material, convert the color node to a parameter and then you can change the color either per instance, or at runtime. If you have any other questions or this was not the answer that you were looking for just respond with a comment and I will be happy to look into this further for you.
Thanks,