Screenshot of the demo, with the feColorMatrix primitive using the values from an input[type=color] (which are also displayed in the hex. RGB and percentage RGB formats), a button to copy the SVG filter to clipboard, a visual test area and options to select what the filter gets applied on (text + emojis or a CSS gradient or a .png with transparency or a fully opaque .jpg).
https://files.mastodon.social/media_attachments/files/112/157/556/099/888/345/original/a5b76dc9629cf71c.png