Makes me think of Japanese 噂 uwasa "rumor, gossip", although it doesn't appear to be onomatopoeic (even though Japanese has a LOT of lexicalized onomatopoeias, very commonly turned into verbs).But Arabic does have some nice onomatopoeic verbs. The first one I came across (and I've mentioned it elsewhere) was وسوس, waswasa, "to whisper". It's something the Devil likes to do.
If it is related to yellow, it must be a loan, otherwise it should have initial h-; the regular cognate is helvus.Who knew that Latin had a (rare) word cognate with "yellow"? Gilvus. Maybe of Celtic origin (according to the OLD).
I didn't know that one either. It seems equally rare as gilvus.helvus
Oh dear.