Crimson sits next to 3 phonetic neighbors — Crystal, Carmen, and Crispin are the closest matches by sound. Most share Crimson's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"deep purplish-red color"
"to obtain, to receive"
"child of heaven, celestial child"
"God may protect"
"slender, lean"
"one from the hollow or nook"
"grace, blessing (Japanese 恵奈)"
"my God is Yahweh"
"short form of Josephine"
"gift from God"
"enclosed garden, place of perfect happiness"
"divine, heavenly"
"blue"
"possessing goodness"
"oak tree, terebinth"
"from the hills, hill settlement (Bray) combined with -lin (diminutive)"
"light, radiance, splendor"
"God's heart, divine accord"
"woodland clearing with hares"
"peace, harmony"
"falling, flowing motion"
Similar sound: These names share phonetic patterns with Crimson — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Arabic qirmiz via Medieval Latin origins, giving them the same cultural heritage as Crimson.
Rhythm: Crimson is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.