This is my observation and understanding. A technical explanation of the calculations would be intriguing. Utilizing the CombineRGB node provides the nearest approximation of the value interactions.

Conduct a Superfly progressive render of the Dawn 2 base skin shader and monitor the behavior of the Subsurface scattering. The RGB Radius values are set to 1, 0, 0. During the rendering process, you will observe that the skin shader primarily exhibits green and blue scattering due to its zero-radius value, while the red scatter is minimally visible owing to its penetration distance, and the reflectance radius value fixed at one.