Problem and difference between material color and vertex color

I need to use color of the vertices in the buffer geometry and switch back to the material color. I set material color(hex from Three.Color) and vertices’ colors(r.g.b float from Three.Color) they are the same and there is a difference(pic 1 - material color, pic 2 - vertices’ color).
Vertices’ color always give a darker shade.

Could anyone explain to me why there is such a difference in color shades between these two methods and how to fix it?

Even if you define vertex colors, they are always multiplied with the color value of the material. So you have to ensure color is set to 0xffffff to avoid any influence on the vertex colors.

For more details, it would be helpful if you share a live example that demonstrates the issue.

Thanks a lot. It is very helpful!