That looks quite beautiful! There’s a lot of things you can do to change how scenes look in CesiumJS. I’ve been meaning to write up a little guide on that on the forum here.
The closest thing I have is to turn on globe lighting, change the time of day, and then change the lighting/skybox. I did that to get this project here to match the photographs a bit: Projecting country flags on Matterhorn mountain
You may find this lighting example useful: https://sandcastle.cesium.com/index.html?src=Lighting.html
If you do get some success with this I’d love to see how it turned out!