Help on script mesh graphics

I’m trying to make a procedural generation using hexagons,
For that I generate them with a script that uses meshes.
My problem is that the rendering is too smooth, I would like to have a rendering without the shadow that gives an impression not flat. I would like to have a flat rendering like on the second picture.
thanks in advance for the help

@Letju34 Try turning on auto generate in the lighting tab and maybe turn up the intensity on your light source.