Artwork
Here is some artwork for FreeCAD. Feel free to reuse in other applications...
Color chart
for more guidelines to make Icons in FreeCAD see the Gui Command page
Icons
Application icon
Part icons
Draft icons
View icons
Zoom icons
File:View-zoom-selection.svg File:View-zoom-border.svg File:View-zoom-all.svg
Tree Icons
File:Tree Mesh.svg File:Tree Selectable.svg File:Tree Unselectable.svg
Workbench icons
Sketcher icons
File:Sketcher Polyline.svg File:Sketcher Rectangle.svg File:Sketcher Text.svg