As not all software functions the same as QGIS and for display purposes it is proposed to create the SVG optimized for QGIS but have a python script that produces a normal rendering version viewable in Inkscape and other software including a PNG option
SVG in the repository are in theory created to be used with QGIS and thus use techniques as described in the following documents for leveraging QGIS to alter colors https://blog.sourcepole.ch/2011/06/30/svg-symbols-in-qgis-with-modifiable-colors/ https://www.sigterritoires.fr/index.php/en/how-to-make-an-svg-symbol-editable-color-stroke-in-qgis/
As not all software functions the same as QGIS and for display purposes it is proposed to create the SVG optimized for QGIS but have a python script that produces a normal rendering version viewable in Inkscape and other software including a PNG option