Where does “φέρετρο” come from?

φέρετρο (Greek) comes from Koine Greek φέρετρον, from Ancient Greek φέρετρον, from Ancient Greek φέρω, from Proto-Hellenic pʰérō, from Proto-Indo-European bʰéreti, from Proto-Indo-European bʰēr- — shiny, light brown.

φέρετρο (Greek): coffin, casket