白 is ancient and debated: a rising sun's first ray, a thumbnail, a grain of white rice — pick your scholar. Whatever it drew, it has meant white, bright and plain for three thousand years.
白 is loaded: white is the color of funerals in tradition (brides wore red; white was for mourning), yet 白 also means 'plain' (白开水, plain boiled water — China's default beverage), 'free/in vain' (白吃, eat for free; 白学了, studied for nothing), and 'clear' (明白, understand — 'bright-white'). The poet 李白 Li Bai carries it in his name: 'Li the White', drinking to the bright moon.
Dawn's first WHITE ray — bright, plain, clear.
白开水 'white boiled water' is China's cure-all: 多喝热水 ('drink more hot water') is the national prescription for everything.