<div class="wrapper">
  <div class="item">Primary</div>
  <div class="item">On Primary</div>
  <div class="item">Surface1</div>
  <div class="item">Surface2</div>
  <div class="item">Surface3</div>
  <div class="item">Surface4</div>
  <div class="item">Shadow</div>
</div>
<pre class="language-css">
<code>
:root {
  --primary-hue: 250;
  --primary-saturation: 100%;
  --primary-lightness: 90%;
  --primary-dim: hsl(
    var(--primary-hue) calc(var(--primary-saturation) / 1.5)
      calc(var(--primary-lightness) / 3.5)
  );
  --on-primary-dim: hsl(var(--primary-hue) 35% 90%);

  --surface1-dim: hsl(var(--primary-hue) 40% 20%);
  --surface2-dim: hsl(var(--primary-hue) 40% 25%);
  --surface3-dim: hsl(var(--primary-hue) 30% 30%);
  --surface4-dim: hsl(var(--primary-hue) 30% 35%);

  --surface-shadow-dim: var(--primary-hue) 40% 10%;
  --shadow-strength-dim: 0.25;
}
</code>
</pre>

@import url("https://fonts.googleapis.com/css2?family=Exo:wght@600&display=swap");

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  width: 100vw;
  min-height: 100vh;
  font-family: "Exo", Arial, sans-serif;
  background-color: #557;
  padding: 20px;

  display: grid;
  gap: 10px;
  place-content: center;
}

:root {
  --primary-hue: 250;
  --primary-saturation: 100%;
  --primary-lightness: 90%;
  --primary-dim: hsl(
    var(--primary-hue) calc(var(--primary-saturation) / 1.5)
      calc(var(--primary-lightness) / 3.5)
  );
  --on-primary-dim: hsl(var(--primary-hue) 35% 90%);

  --surface1-dim: hsl(var(--primary-hue) 40% 20%);
  --surface2-dim: hsl(var(--primary-hue) 40% 25%);
  --surface3-dim: hsl(var(--primary-hue) 30% 30%);
  --surface4-dim: hsl(var(--primary-hue) 30% 35%);

  --surface-shadow-dim: var(--primary-hue) 40% 10%;
  --shadow-strength-dim: 0.25;
}

.wrapper {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 10px;
}

.item {
  width: 20vmin;
  margin: 0 auto;
  aspect-ratio: 1 / 1;
  border-radius: 50%;
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 14px;
  color: var(--on-primary-dim);
}

.item:nth-child(1) {
  background-color: var(--primary-dim);
}

.item:nth-child(2) {
  background-color: var(--on-primary-dim);
  color: #000;
}

.item:nth-child(3) {
  background-color: var(--surface1-dim);
}

.item:nth-child(4) {
  background-color: var(--surface2-dim);
}

.item:nth-child(5) {
  background-color: var(--surface3-dim);
}

.item:nth-child(6) {
  background-color: var(--surface4-dim);
}

.item:nth-child(7) {
  background-color: hsl(var(--surface-shadow-dim) / var(--shadow-strength-dim));
}