Question Wrong colors in attempt to recreate Unity's color picker (linear/gamma space issue ?)

So as the title says I'm trying to somehow recreate the Unity's picker color in my project.
I dont use the Shader Graph quit often and I'm bad at writing shaders.
You can see in the capture that the result I get is not what I should get.
My project is in Linear color space and I think this is related to my shader issue.
Is there a magic button somewhere to convert my shader to the right color space ?
Or maybe I have to hardcode some power() in the shader to correct the color ?
[EDIT]
with a second look, if it were a color space issue, I should at least get pure white at the extrem left part of the saturation preview, but I have grey. so really I don't know whats wrong here.
[EDIT 2]
I did a wrong use of the saturation node. I think it can not output white from a red color.

 

got it.