Sketcher > Setting Sketcher Environment > To Set Sketcher Color
  
To Set Sketcher Color
To change the default color of section geometry, perform one of these operations:
Set the configuration option section_color.
Click File > Options > System Appearance > Sketcher. Select a color for Geometry.
Before opening a design, click System Appearance > Sketcher. Select a color for Geometry.
The new color applies to both new and modified geometry.