The answer to the question you are almost certainly asking me is, unfortunately, not what you probably want to hear.
I custom mix all my colors to an existing sample of either what was specifically used by the production, what the modeling community has agreed by consensus was the color used if the information on exact colors are not available/in production, or by eye when nothing else is available to reference. I do not keep “recipes” of the colors, I do not know how to guide your color mixing unfortunately, and the only thing I can honestly suggest is that you do what I did. Practice. Constantly. And do not be afraid to fail, be prepared for non-constructive criticism and be prepared to hear you are “wrong”… but do it for yourself or your client, always. Always. Anything else is noise.
I took color theory classes in college, and spent most of my life working in multiple paint mediums to understand their behaviors and interactions. I worked in the at supply field from 1987 to 1998, and have used almost every paint and binder under the sun with varying degrees of success. I take this lifetime of knowledge and apply it to the work I do now, and am still learning and growing every day! And yes, I constantly fail. “It’s too dark” will be on my gravestone, if the internet has any thing to say about it.
I hope this helps you!