Indigo sits next to 3 phonetic neighbors — Indio, Iggy, and Diego are the closest matches by sound. Most share Indigo's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"blue-purple dye, the color indigo"
"serpent's mouth"
"growth, abundance, increase"
"little fire (from Irish aodh)"
"badger settlement"
"variant of Pearson: son of Piers"
"little king"
"little rock"
"bright-headed warrior"
"crooked hill; bent (cam) nose (sron)"
"God has been gracious"
"word name from archery term"
"tailor, cutter of cloth"
"people of gentle birth"
"gift of God"
"fair, attractive"
"ruler of the people"
"who is like God (via Michael)"
"hound of the plain"
"descendant of Riagán"
"from the pool or marsh"
Similar sound: These names share phonetic patterns with Indigo — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Greek via Latin origins, giving them the same cultural heritage as Indigo.
Rhythm: Indigo is a 3-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.