A couple of years ago, I made this @codepen demo:
https://codepen.io/thebabydino/pen/RwdjEBW

Since `flood-color` can be animated from the #CSS, this made it more flexible than methods where the two tones were baked into the #SVG #filter as decimal representations of their percentage RGB values.

If you're unfamiliar with those older methods, here are some links, in chronological oder:

👉 https://css-tricks.com/color-filters-can-turn-your-gray-skies-blue/

👉 https://css-tricks.com/using-svg-to-create-a-duotone-image-effect/

👉 https://tympanus.net/codrops/2019/02/05/svg-filter-effects-duotone-images-with-fecomponenttransfer/

👉 https://utilitybend.com/blog/revisiting-svg-filters-my-forgotten-powerhouse-for-duotones-noise-and-other-effects/

#duotone