Vertex Color change in trigger

Hello,

I would to know if it is possible to change the Vertex Color of Vertices of a Mesh (A) which enter a certain Trigger (B).

If it is possible I would also like to know if the color can return to normal if the Mesh(A) leaves the Trigger(B).

Please see pictures for visual representation.

Before entering Trigger

When Entering or leaving Trigger

I know the Visuals aren't exactly as how it works. It's just for the idea ;)

Thank you in advance