attached you’ll see two images of an identical scene, the first with AmbientLight disabled, the second with AmbientLight enabled. I have tried to vary the last distance parameter but problem didn’t disappear.
If you’re using Lighting.j3md you might want to set Shininess to something around 500-1000. I know that helped me with a similar issue. You can play with that number to get different results.
If you’re not using Lighting.j3md then I’m not sure. What shader are you using?
The color is white, there is only one other light and this is a point light which lightens the scene you see in first image. There must be an option to decrease the resulting intensity.