Simple answer: There is no physical basis, it's style
Pedantic answer: Unless the light source is has different colors on different sides
Complex answer: Kind of. Even a linear color fade (from reality) can turn non-linear (and therefore induce color effects) when pushed through a color grading pipeline. So if you count e.g. film emulation as a "physical effect", then yes.
Not sure it happens with the sun, but if you have differently located light sources of different colors you can get shadows of different colors (because the shadow area is one source being blocked but it is still illuminated by the other sources)
This seems more like a chromatic aberration "hack" for HDR landscapes (intensely-lit portions of the scene would have color fringing apparent at the boundaries of light/dark due to dispersion in the observer's lens).
(And it's def a style choice, looks cool when done right! :))
Came to ask this. I suppose if the edge of the sun glows in a different color than the rest, it would tint the edge of the shadow too? So maybe appropriate for sunsets, where the sky near the sun is red but the sun itself still glows bright white. Honestly just guessing.
Pedantic answer: Unless the light source is has different colors on different sides
Complex answer: Kind of. Even a linear color fade (from reality) can turn non-linear (and therefore induce color effects) when pushed through a color grading pipeline. So if you count e.g. film emulation as a "physical effect", then yes.
(And it's def a style choice, looks cool when done right! :))
https://en.wikipedia.org/wiki/Chromatic_aberration