Explore how your colors may appear to others

What each simulation shows you

Often called color blindness simulation, these previews help illustrate how different types of color vision deficiency can affect the appearance of a palette.

• Protanopia

  Simulates the absence of functioning long-wavelength-sensitive (L) cones, making certain reds and greens difficult to distinguish and changing how many red-containing colors appear.

• Deuteranopia

  Simulates the absence of functioning medium-wavelength-sensitive (M) cones, also affecting red–green discrimination, but producing different color shifts from protanopia.

• Tritanopia

  Simulates the absence of functioning short-wavelength-sensitive (S) cones, affecting blue–yellow discrimination and changing how some blues, greens, yellows, and purples appear.

• Achromatopsia

  Simulates the absence of color perception, allowing you to examine differences primarily through lightness rather than hue.

Check colors wherever you're working with them

Color-vision simulation is available directly within Suisai's palette windows, Color Bench, and Nōtan contrast checker.

Switch between typical vision and the four simulation modes directly within your palettes, Color Bench, or Nōtan contrast checker. The simulation changes how the colors are displayed without modifying their underlying values.

Only the colors you're working with are simulated; the surrounding application interface remains unchanged. You can move between modes using the menu, window controls, or keyboard shortcuts, and return to the original appearance at any time.

When color alone isn't enough

Imagine a chart with two data series distinguished only by their colors, or a form where green indicates success and red indicates an error.

Those distinctions may be obvious under typical color vision, but they can become less apparent under certain types of color vision deficiency.

Simulating different viewing conditions can help you identify where additional visual cues may be useful, such as labels, symbols, patterns, or differences in lightness.

You can also examine brand palettes, interface states, diagrams, and other color combinations before committing them to a design.

The goal isn't to avoid particular colors. It's to make sure important information doesn't depend entirely on someone distinguishing between them.

Another perspective, not a final verdict

Color-vision simulations are approximations. They help you explore how colors may appear under different viewing conditions, but they cannot represent every individual's experience.

They're most useful as an additional design check, alongside contrast measurement, clear visual hierarchy, and other accessibility considerations.

For measurable text and interface contrast, Suisai also includes Nōtan, its WCAG 2.2 contrast checker, with Pair, Matrix, and Reach tools.

Together, they provide different kinds of information to help you make better-informed color decisions.

Color is one part of the picture

Simulation tells you how your colors may be seen. These pages cover the rest of what Suisai does with them, from measured contrast to building the palette in the first place.

• Check color contrast →Every pair graded against WCAG 2.2, free in the browser.
• Build and edit palettes →Create colors, name them, and edit the palette files you already have.
• Explore color harmonies →Create related color combinations, ramps, and spectral pigment mixes.

See your colors from another perspective.

Four simulation modes — protanopia, deuteranopia, tritanopia, and achromatopsia — in your palettes, the Color Bench, and Nōtan's contrast checker. Switch between them as you work, and your original color values stay exactly as they are.

One purchase. No subscription. No account or analytics. Your colors stay on your Mac.

If Suisai isn't right for you, a full refund is available within 30 days for direct purchases via Paddle. No reason needed.

macOS 14 or later · Universal · One-time purchase