Deuteranopia Simulator

Deuteranopia Simulator shows a color beside the same color as a deuteranopic viewer would see it, using the deuteranopia matrix the tool's engine applies.

What is Deuteranopia Simulator?

Deuteranopia Simulator takes one color and renders it twice: once untouched, and once as a deuteranopic viewer would see it. The two large swatches sit side by side, so the answer to the only question the page asks is impossible to miss, and the hex value of the simulated result is there when you need to record it.

Deuteranopia is the absence of the medium-wavelength cone, and it is the most common of the complete deficiencies. What it removes is the separation between red and green, which means:

• Reds and greens converge on a similar yellowish tone, and the distinction between them largely disappears.
• Hues that sit between red and green, such as oranges and browns, shift rather than vanish, because their luminance is still doing work.
• Blues and yellows are largely unaffected, since they depend on the short-wavelength cone instead.
• Lightness is preserved throughout, which is why a well-designed palette can survive this deficiency purely on luminance.

The simulated swatch is produced by a fixed three-by-three matrix applied to the 8-bit red, green and blue channels. Its first row is 0.625 red plus 0.375 green, its second is 0.7 red plus 0.3 green, and its third is 0.3 green plus 0.7 blue. The results are clamped back into the 0 to 255 range, and the output is converted to hex so it can be copied directly. That matrix is an approximation of how deuteranopia is typically modelled, not a measurement of any individual's vision, and it is applied at full strength with no severity control.

Because the page is built around a single comparison, its boundaries are narrow.

• Only deuteranopia is simulated. Other deficiencies need their own pages or the multi-type simulator.
• The view is one color at a time. A palette has to be checked color by color.
• There is no image mode, so a screenshot cannot be run through this matrix here.
• Full strength only, with no slider for the partial form that deuteranomaly describes.
• The simulated swatch is what the matrix produces, not a prediction of what a specific person will perceive.

Use this page when red and green are both load-bearing in a design, which is the situation deuteranopia punishes most. Compare the swatch pair, then look at the hex value of the simulated color and ask whether it sits far enough from its neighbours in lightness. If the two swatches differ mainly in hue and barely in lightness, that is the case worth fixing, because lightness is the only channel this deficiency reliably leaves intact.

As a green cone simulation the page is narrow on purpose: it converts one color once and shows the result, rather than ranking a palette or scoring a design. That makes the deuteranopia hex value printed beneath the swatch the most portable output it produces, and it is worth copying for any color destined for a dark surface or a print run. What the page cannot say is whether the conversion is acceptable in context, since a cvd deuteranopia result that looks fine in isolation can still collapse against a neighbouring color in a real chart.

How to use Deuteranopia Simulator

1. Enter the color you want to test in the swatch field.
2. Read the two large swatches side by side, with the original labelled on the left and the simulated result on the right.
3. Note the hex value printed under the simulated swatch if you need to record the result.
4. Compare the lightness of the simulated color with the other colors it will sit next to, since that is the channel deuteranopia leaves working.

When to use Deuteranopia Simulator vs related tools

Use the deuteranopia simulator when red and green both carry meaning in a design and you want the single most common deficiency checked directly. The partial form is covered by the deuteranomaly simulator, the other complete deficiency that affects red and green is the protanopia simulator, all four types together including the image mode are on the color blindness simulator, and choosing colors that survive the problem in the first place is the color blind friendly color picker.

Privacy & Security

This tool runs entirely in your browser — no data ever leaves your device. There is no server round-trip, no upload, no logging, and no account required. Your input is processed locally using client-side JavaScript and is never stored, transmitted, or accessible to anyone else. When you close the tab, everything disappears.

Frequently asked questions about Deuteranopia Simulator