Hi UUMANG ,
It looks like it is mostly because of the colors and placement of your Color Ramp Flags (the right flag is very close to white)....But the lighting might also have a significant effect and your Translucent Shader is mixed in with a rather high Factor (0.500) and you also have a Clearcoat of 0.222 and that might give some more reflection of environmental light...
Sometimes small tweaks can have a huge effect.
You also don't need to achieve the exact same result as it is on the screen. I understand that some alarms might ring in your head if you see different results, but as long as you're not doing anything wrong. But it's hard to judge when you're a beginner, that's the tricky part. But as long as it's an aesthetic thing, don't worry about it, everyone will do things differently.