Red Stripe is a tool to help people with a red-green color blindness differentiate colors. Move the filter window over something on screen to add continous stripes on reds and dashed stripes on greens.
The window is totally transparent, to colors as well as to your mouse pointer. You can at all times click through the filter window to reach apps and windows that are below it.
Stripes are good to distinguish other colors too depending on whether they their tint are more red or more green, such as purple and turquoise. Adjust stripes to better nail certain colors: stripes can be hidden, or show up with loose or tight spacing.
Filter speed is good enough to allow a video to play through it. If needed, you can adjust the refresh speed to save energy or reduce the lag.
FOLLOW THE MOUSE
You can also tell Red Stripe to follow the mouse pointer and display its suroundings. This will let you compare the filtered view with the unaltered original under the pointer. This can also be useful to avoid moving the window.
Red Stripe is also available for iOS.