<!DOCTYPE HTML> <head> <style> .parent { width: 200px; height: 200px; isolation: isolate; background: #5856a2; } .child { width: 200px; height: 200px; mix-blend-mode: soft-light; opacity: 0.5; background: white; will-change: opacity; } </style> </head> <body> <div class="parent"> <div class="child"> </div> </div> </body>