According to Shuowen, it is both a phono-semantic compound (形聲, OC *ɡʷaːŋ) and ideogrammic compound (會意): phonetic 炗(“light”) + semantic 田(“field”) – the color of earth, with 炗 being the ancient form of 光 (OC *kʷaːŋ, *kʷaːŋs, “light”). However, this interpretation is likely erroneous as 廿 at the top was formed as a result of corruption of 口 in the bronze inscription.
Chi (2010) proposes that 黃 was originally a pictogram (象形) and the original character of 尪 (OC *qʷaːŋ, “a disabled person with a protruding chest or abdomen”). It has been phonetically borrowed for "yellow" since the era of the oracle bone script. He (1998) noted the possible ritual of burning disabled people with a protruding chest or abdomen to pray for rain as mentioned in Zuozhuan. The 口 in the upper part of the bronze inscription of 黃 might be depicting the disabled person's face facing upwards.
Li (2012), on the other hand, proposes that 黃 was originally a pictogram (象形) and the original character of 璜 (OC *ɡʷaːŋ, “semicircular jade”) as the 口 in the oracle bone script resembles a ring of jade, so the character would carry the meaning of "a man wearing a ring of jade on his chest". The meaning "yellow" is the result of rebus.
Red and yellow, black and white, they are precious in His sight—Jesus loves the little children of the world. [original English lyrics] No matter red, yellow, black, white, they are all treasured in Jesus' heart—Jesus loves all the children of the world. [literal English translation]