Latin word solem comes from Proto-Indo-European *sor-

Detailed word origin of solem

Dictionary entry	Language	Definition
*sor-	Proto-Indo-European (ine-pro)	red, rosy, pink
*sēl-	Proto-Indo-European (ine-pro)	to calm, quiet, be favourable
*swōl	Proto-Italic (itc-pro)
solem	Latin (lat)