Looks like a copy and paste error from the RGBW section below it. This was sending the minimum value of (r,g,b) to w which on a fully saturated color was often zero. This fix sets it to the average, although some sources online say it should be an uneven weighting formula such as (W = R^gamma .2126 + G^gamma .7152 + B^gamma * .0722).
Looks like a copy and paste error from the RGBW section below it. This was sending the minimum value of (r,g,b) to w which on a fully saturated color was often zero. This fix sets it to the average, although some sources online say it should be an uneven weighting formula such as (W = R^gamma .2126 + G^gamma .7152 + B^gamma * .0722).