Filters list (Syntaw)
filter: none | blur() | brightness() | contrast() | drop-shadow() | grayscale() | hue-rotate() | invert() | opacity() | saturate() | sepia() | url();
Examples:
Convert block/image ... to black and white (Gray out):
Step 1. Create your module and Block (/tutoriels/107/create-a-simple-block-programmatically)
.modal-backdrop {
background-color: transparent;
}