To spice things up a little bit, games would include a thin plastic overlay you could put over the screen to give the game faux colors ... show the kind of visual effects that are possible.

LetMeReShade is a free plugin that makes it easy to apply shaders and tweak graphical settings on compatible Steam Deck games ...

The Effects menu in the Effects tab only offers one color-changing tool: Duotone. Duotone offers over 20 dual-color overlays to place on your image. Once any are selected, you can edit the color ...