Latin word picta comes from Proto-Indo-European *peyḱ-

Detailed word origin of picta

Dictionary entry	Language	Definition
*peyḱ-	Proto-Indo-European (ine-pro)
*piḱ-tó-s	Proto-Indo-European (ine-pro)
*pi-né-ḱ-ti ~ pi-n-ḱ-énti	Proto-Indo-European (ine-pro)
pingo	Latin (lat)	I decorate or embellish. I paint, tint or colour. I portray.
*piktos	Proto-Italic (itc-pro)
pictus	Latin (lat)
picta	Latin (lat)