Specs are quantitative aspects of the option such as the price
Pros
Pro
Preserves all colors
Unlike a red overlay, this app converts all screen colors to grayscale first, then shades them red, so completely green text becomes a shade of red rather than becoming unreadable black.
The master color filter setting also has an option for colorblindness enhancement, with settings for protanopia/anomaly, deuteranopia/anomaly and tritanopia/anomaly. These options in theory enhance clarity and color detail.