Hi,
how to get automaticly a darker shading of the Base Color for Shadow Color? So that i don´t need to set a Shadow Color.
I don´t mean just change the value to darker:

I mean a darker shading like this

Best regards,
René
Use a color correction to derive the second value from the first—then a single color choice can generate as many variants as you need, depending on how many different “recipes” you want to put it through. In this case I’m multiplying down the color to get a darker variant, but you could just as easily multiply it up, or desaturate it, or tint it greener—all operating off the initial color choice.
You’re overcomplicating it- just multiply your base color with itself