Surface extrusion yellow color on one side

[robertVZLY9]

I created a surface. then thickened it.  The top looks fine but i still see the yellow surface or whatever is left on the bottom.  If anyone knows how to fix this, please help. the first picture is the bottom it has the yellow i want to remove.  the second picture shows the top view it is correct.

Thanks so much.

Happy Monday!!

Rob

[TheCADWhisperer · Accepted solution]

The Thicken created a Solid Body.

Now turn off the Visibility (right click) of the Surface Body.

[robertVZLY9]

thank you!