Blu sits next to 4 phonetic neighbors — Blue, Bleu, and Boo are the closest matches by sound. Most share Blu's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"the color blue"
"complete, pure"
"gracious, gentle"
"little street, alley"
"heavenly breath, breath of heaven"
"combination of Renée (reborn) and Esme (beloved/esteemed)"
"son of John, God is gracious"
"illusion, magic"
"noble birth, people of high social standing"
"noble, adorned"
"settlement of Kari's people"
"God has favored me"
"of the Jenkin family"
"harmony, concord, fitting together"
"park by the lake"
"jasmine flower"
"black, dark"
"strength, hill (from Irish Bree)"
"modern invented name"
"God is my light"
"little rose"
Similar sound: These names share phonetic patterns with Blu — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Italian/English origins, giving them the same cultural heritage as Blu.
Rhythm: Blu is a 1-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.