Custom preview color problem

hi …
when I use the custom preview component in Grasshopper and see the viewport I see that every color I selected for each object has a border color that is very close to the selected color but is a little darker … and because I want use the output in an AI algorithm that is so sensitive to the color I must correct it.

If you use nurbs surfaces then what you see with a different shade of your desired colour are the isolines.
There’s no way around it as far as I know. The common workaround is to convert the surfaces to meshes and connect those in the Custom Preview.

thank you but I cant do it because I am going to use a wide range of shapes to generate a dataset.