These fields define the default settings for Parts. Whenever a Part is added it uses these defaults.
Foreground Colour
The foreground colour of the Part. This colour is used to create the outline of Part such as for a rectangle Part.
Background Colour
The background colour is the colour used for the background of a Part. In some cases it is the colour used to fill in a Part such as a rectangle Part.
Stroke Width
This is the width of the line used to draw a Part that has a shape such as a Rectangle. The foreground colour is used to draw the Part.