Sky demo looks so bright

In this demo three.js examples . the sky looks so bright when sun rises, even looks white. I remember the sky was blue when the demo was first published a few years ago. Does anyone know what happened?

The demo uses a different tone mapping and also a different parameterization.

This is how the demo looks with r90 (four years old) :three.js webgl - shaders - sky sun shader

Some settings

the sky is more blue, but the dusk is lost. I think the rayleigh and mie parameters is now proper and can’t be modified, the shader can’t display a noramal sky whatever the tonemapping and the color encoding are set.

I tried to modify the value of every parameter, and there is not a proper setting for a good looking sky.

this version and setting can get a pretty good look, but no tonemapping.