Yellowknife (English) comes from English yellow, from Middle English yelow, from Old English ġeolu, from Proto-West Germanic gelu, from Proto-Germanic gelwaz, from Proto-Indo-European ǵʰelh₃wós, from Proto-Indo-European ǵʰelh₃- — to flourish; green, yellow.
Ancestry of “Yellowknife”, step by step
Yellowknife traces back through 3 separate lines of ancestry.