RGB -> Oklch colors are off

[atomicptr]

Hello,

I've noticed that when converting from RGB to oklch the resulting color is somewhat off, here is an example:

<?php

require "vendor/autoload.php";

use matthieumastadenis\couleur\ColorFactory;
use matthieumastadenis\couleur\colors\OkLch;

$color = ColorFactory::newCss("#75a7d1");
$oklch = $color->toOkLch();

echo "oklch({$oklch->lightness}% {$oklch->chroma} {$oklch->hue})";

This returns:

oklch(67.462201399088% 0.14135681535913 261.33802091148)

for me but it should be:

oklch(70.9% 0.082 244.65)

See: https://oklch.com/#70.9,0.082,244.65,100

Not sure if I'm doing something wrong here