Protanopia: Inability to perceive red light. Reds appear black, and oranges/yellows/greens appear shifted toward yellow.
Deuteranopia: Inability to perceive green light. Similar to protanopia but without the darkening of reds.
Tritanopia: Inability to perceive blue light. Blues appear greenish, and yellows appear pinkish.
Achromatopsia: Complete color blindness where only shades of gray are visible.
This tool simulates these conditions to help designers create more accessible color schemes that work for all users.