hah, awesome, I know exactly what issue this is without clicking through - Myndex is wrong on this, shockingly, but unfortunately my lips have to be sealed, for now.
Look into the correspondence between the space Myndex uses, the space contrast ratio is measured in, and then again at the W3C docs: TL;DR Myndex's approach doesn't account for reflectance off the screen
Look into the correspondence between the space Myndex uses, the space contrast ratio is measured in, and then again at the W3C docs: TL;DR Myndex's approach doesn't account for reflectance off the screen