<style>
img {
    -webkit-transform:translateZ(0);
}
</style>
<img style="filter: grayscale(0)" src="resources/reference.png">
<img style="filter: grayscale(0.2)" src="resources/reference.png">
<img style="filter: grayscale(0.4)" src="resources/reference.png">
<img style="filter: grayscale(0.6)" src="resources/reference.png">
<img style="filter: grayscale(0.8)" src="resources/reference.png">
<img style="filter: grayscale(1.0)" src="resources/reference.png">