CSS only color filter
This filter is CSS only and allows quick filtering online without the need for a photoshop intermediate.
How it works:
Base layer: background image wrapped in a div container. No tricks here.
B&W filter -- ::before element Using absolute positioning a white filter is applied on top of the base image with opacity 100% and with mix-blend-mode set to hue. This created a B&W effect.
Color Overlay -- ::after element Using absolute positioning a red filter is applied on top of these layers (z-index: 3) a red layer is applied. To soften the effect, the opacity is lowered and mix-blend-mode set to screen. Color burn, darken and multiply produce similar effects.
The animation on hover is created by animating the opacity of the before and after pseudo elements from 0 to their final states.