https://gis.stackexchange.com/questions/32271/creating-new-custom-vector-marker-symbol-for-arcmap
- Make vector graphic in inkscape
- save as EMF (Enhanced metafile) - transform fonts to outlines
- In ArcGIS - Symbol Properties --> choose Picture marker Symbol Type --> browse to EMF file
- can't chance the colors in ArcMap
Alternative is to convert it to a font, then you can change the colors.