1. i have put a transmission and the light don't pass in the mesh.
2. the light as not colored when he passed out the mesh.

problem: the light are not colored when he passe out the mesh with transmission and he not got out when he hit the mesh.

As you can see, the beam of light don't pass in the transmission he simply stopped and he not colored

@Pratik Borhade (PratikPB2123) this the wrong result.

It was about how volume interacts with light. But if you meant exactly the color rendition, then I think it would be more logical like this:

In T101448#1426567, @Donovane (Stimes) wrote:

I'm sorry but isn't logical to reduce the alpha for get the result. the transmission ray have clearly a problem.... by default in real life you can't result the alpha of an object and the light pass in ... You have just get around the problem not fixies. and the light fog are already not colored when he pass in the glass material at the output logically is colored in red.... is like a philter... conclusion this task is definitively not closed and not resolved....

@Clément Foucault (fclem) CCan you see that please also @Jeroen Bakker (jbakker)

Hm. Really. I'm sorry, I thought you needed to work this out. In that case, according to the documentation:
Controls the transparency of the surface, with 1.0 fully opaque. Usually linked to the Alpha output of an Image Texture node.
It appears to be a technical type of transparency designed specifically for textures.
That is, it does not produce any physical reactions with light, but simply passes it through. You need to use shaders that implement exactly the transmission of light with interaction with it.

FOR EEEVEE ! For some reasons in the shader when you change the shadown mode opaque to none, the light pass throught the mesh but is not colored.... But here we want a shadow and the light pass throught the mesh and colored the mean light when he passe throught the "Mesh" with transmission . when the light are passed throught the mesh the mean light must be colored by the color of the transmission. But here not.

And in cycles nothing works the light not pass throught the mesh and stay not colored too.

Eevee does not support colored shadows. So this behavior is impossible to reproduce.

Is there any other reason for this report?
I correctly understood that:
The Transparency Behavior of the Principled BSDF node is not required to create any kind of physical reaction of the light to the surface in order to have a colored shadow.
To do this, you need to use special shaders.
It won't work for eevee, so just cycles and special translucency shaders.

So for now the report does not describe any bug...