I have a form of color vision deficiency called Protanomaly. This means that the cones in my eyes that are supposed to see red are a little bit worse at it than they should be - especially outside of the center of my vision. So when an object or UI element in a game is supposed to stand out and draw my attention (flashing red low health meters, red text, enemy outlines, enemy attack tracers, or circles indicating an incoming AOE attack), it instead tends to blend in with the background. In some games, it can be a pretty big disadvantage. So as a programmer, I've written a few things that can make games a little bit more playable.
The most useful tool is a shader that replaces pixels of a range of colors close to reds with either yellows or greens. Note that anti-cheat methods in some games have been known to block ReShade from working. Overwatch, in particular, intentionally crashes the game when ReShade attempts to inject. Still, it can be useful for games such as the FarCry series, Paladins, Quake Champions, Guild Wars 2, and more.
When that isn't an option, I also have a script that toggles the configuration of NVidia's Digital Vibrance and Hue Shift on the press of a hot key. Digital Vibrance can be used to artificially raise the contrast of the screen, which I've found helps make some colors stand out. Hue shift is a setting that effectively spins the color wheel and re-maps what every color is. Unfortunately, Hue shift can make things look awful in terms of aesthetics, but I have used a shift of 147° to turn reds in Overwatch into greens to assist with my color vision deficiency that makes reds camouflage.