The Proto-Indo-European root *ǵʰel- "to shine" in the suffixed zero-grade form *ǵʰl-to- became Proto-Germanic *ǥulþam and English gold.
yellow is from Old English ȝeolu from Proto-Germanic *ǥelwaz, from the suffixed form *ǵʰel-wo-.
The suffixed variant *ǵʰlō-ro- became Greek χλωρός khlōros "greenish-yellow", then χλόη khloē, "young green shoot". This is the origin of the name Chloe.
The form ǵʰel-i- became Sanskrit हरि hari meaning a number of things, including "to be yellow or green", "horse", "lion", "the sun", "the wind", and "worshipper of Vishnu". Related to this is Hindi हरे hare, one of the names of Vishnu - as in Hare Krishna.