Isolation With Css Mix-blend-modes: How To Prevent Elements From Blending With Parent

I have tried this a lot of different ways, and cannot make it so that the .pink and .green divs blend with one another, but not the background color of the parent element, .wrapper

Solution 1:

I would consdier an extra wrapper where you set a z-index in order to create a staking context thus the element will no more blend with the blue element:

.wrapper {
  background-color: blue;
  height: 100vh;
  width: 100%;
}
.wrapper > div {
  position:absolute;
  height: 100vh;
  left:0;
  right:0;
  z-index:0;
  top:0;
}

.pink {
  background: hotpink;
  height: 80%;
  width: 50%;
  position: absolute;
  z-index: 1;
  top: 0;
  left: 10%;
  mix-blend-mode: multiply;
}

.green {
  background: limegreen;
  height: 80%;
  width: 50%;
  position: absolute;
  z-index: 1;
  top: 0;
  right: 10%;
  mix-blend-mode: multiply;
}

<divclass="wrapper"><div><divclass="pink"></div><divclass="green"></div></div></div>

Everything in CSS that creates a stacking context must be considered an ‘isolated’ group. HTML elements themselves should not create groups.

An element that has blending applied, must blend with all the underlying content of the stacking context [CSS21] that that element belongs to.

So the main trick is to have the elements in a stacking context where the blue element doesn't belong. If the wrapper element is their direct parent element it won't be trivial to make them in different stacking context thus the need of an extra wrapper.

---

Isolation won't help you, because it will simply make the wrapper creating a stacking context, so it won't isolate the wrapper from its child but from all the elements outside. if you apply it to the extra wrapper it will work exactly like setting z-index or any other property that create a stacking context.

.wrapper {
  background-color: blue;
  height: 100vh;
  width: 100%;
}
.wrapper > div {
  position:absolute;
  height: 100vh;
  left:0;
  right:0;
  isolation:isolate;
  top:0;
}

.pink {
  background: hotpink;
  height: 80%;
  width: 50%;
  position: absolute;
  z-index: 1;
  top: 0;
  left: 10%;
  mix-blend-mode: multiply;
}

.green {
  background: limegreen;
  height: 80%;
  width: 50%;
  position: absolute;
  z-index: 1;
  top: 0;
  right: 10%;
  mix-blend-mode: multiply;
}

<divclass="wrapper"><div><divclass="pink"></div><divclass="green"></div></div></div>