Random colored user backgrounds with auto color calculation

random-color-user.php

<?php

/** Random Color Part Generator HEX **/

function RandomColorPart()
{
    return mt_rand(0, 255);
}

/** Random Color Part Generator **/

/** Random Color Generator **/

function RandomColor()
{
    return [
    "red" => RandomColorPart(),
    "blue" => RandomColorPart(),
    "green" => RandomColorPart()
    ];
}

/** Random Color Generator **/

/** Random Colored Background **/

function RandomColoredBackground($name = "İ")
{
    $bg = RandomColor();
    $div ="<style>
:root {
  --red: ".$bg['red'].";
  --green: ".$bg['blue'].";
  --blue: ".$bg['green'].";

  --accessible-color: calc(
    (
      (
        (
          (var(--red) * 299) +
          (var(--green) * 587) +
          (var(--blue) * 114)
        ) / 1000
      ) - 128
    ) * -1000
  );
}

.outerDiv {
  background-color:
    rgb(
      var(--red),
      var(--green),
      var(--blue)
    );
    width:75px;
    height:75px;
    border-radius:50%;
}

.outerDiv p {
  color:
    rgb(
      var(--accessible-color),
      var(--accessible-color),
      var(--accessible-color)
    );
    line-height:75px;
    text-align:center;
    font-weight:bold;
    font-size:50px;
}</style>"."\n";
    $div .= "<div class=\"outerDiv\"><p>".$name."</p></div>";
    return $div;
}

/** Random Colored Background **/

/** Simple Usage */

echo RandomColoredBackground();

/** Simple Usage */