https://www.w3schools.com/cssref/pr_background-blend-mode.php
CSS background-blend-mode property
Well organized and easy to understand Web building tutorials with lots of examples of how to use HTML, CSS, JavaScript, SQL, PHP, Python, Bootstrap, Java and...
background blend modecssproperty
https://www.w3schools.com/cssref/playdemo.php?filename=playcss_background-blend-mode&preval=darken
W3Schools CSS background-blend-mode demonstration
background blend modecssdemonstration