By the CSS2 standard, #000 and #FFF are sRGB colours, with #000 targeting 0.2cd/m^2, and #FFF targeting 80cd/m^2, with adjustments for ambient light level. Wit

By the CSS2 standard, #000 and #FFF are sRGB colours, with #000 targeting 0.2cd/m^2, and #FFF targeting 80cd/m^2, with adjustments for ambient light level. With CSS4, you can choose other colour-spaces instead. The web standard is there, but so long as 99% of users have setups which emit 300+cd/m^2 and say they're emitting 80, you can't do much with it. The push toward HDR displays gives us another chance to 'get it right' wrt calibration, but a quick google search of 'HDR washed out' demonstrates why it's an uphill battle to get consumer displays to be honest.