img, img.grayscale,
.image-container.grayscale,
.image-container .grayscale {
    filter: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg'><filter id='grayscale'><feColorMatrix type='matrix' values='0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0 0 0 1 0'/></filter></svg>#grayscale"); /* Firefox 10+, Firefox on Android, IE10/IE11 \*/
    filter: gray; /* IE6-9 \*/
    -webkit-filter: grayscale(100%); /* Firefox 37+, Chrome 19+, Safari 6+, Safari 6+ iOS, Android 40 \*/
    filter: grayscale(100%);
}

img:hover, img.colored,
.masonrygrid li img,
.image-container.colored, .image-container.colored img,
.image-container .colored,
.image-container:hover .grayscale,
.tab-wrapper:hover .image-container .grayscale,
figure.colored img, img.mfp-img,
.colored .image-wrap .image img,
.modal-lightbox img, #lightbox img {
    filter: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg'><filter id='grayscale'><feColorMatrix type='matrix' values='1 0 0 0 0, 0 1 0 0 0, 0 0 1 0 0, 0 0 0 1 0'/></filter></svg>#grayscale");
    -webkit-filter: grayscale(0%);
    filter: grayscale(0%);
}