Limit Light on Top of Mesh

[Takemura]

Yo altogether,

I try to find a way to limit my hemispheric light on top of my mesh.

Here the lighting is too strong, white color:

From the side top looks perfect (light grey):

My Playground:

Babylon.js Playground

How can I make it that lighting from top looks like from side?

Edit: I added groundColor to White, so bottom face is not black (same color as sides).

[Takemura]

I found the solution, it is the specular light:

light.specular = BABYLON.Color3.Black();