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Calcimator

Color Blindness Check

Approximate RGB shifts for protanopia, deuteranopia, and tritanopia (Brettel-style simplification).

Inputs

Results

Protan B

50

Protan R151
Protan G149
Deutan R129
Deutan G129
Deutan B50
Tritan R220
Tritan G60
Tritan B60
Rel. luminance93.294
How to Use This Calculator
  1. Enter an RGB color value (0-255 for each channel) you want to test.
  2. Review the simulated RGB values for protanopia, deuteranopia, and tritanopia.
  3. Compare the shifted values to your original to check if your design colors are distinguishable for color-blind users.
  4. Use the relative luminance value to assess WCAG contrast compliance.

How the result changes with Blue 0–255

Blue 0–255Protan B
2626
8989
166166
230230

What each input means

Red 0–255
sRGB red channel.
Green 0–255
sRGB green channel.
Blue 0–255
sRGB blue channel.

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    Red 0–255 = 220, Green 0–255 = 60, Blue 0–255 = 50 = 3 input(s) provided
  2. Calculate Protan B
    Protan B = b
    50 = 50
  3. Calculate Protan R
    Protan R = 0.56667 * r + 0.43333 * g
    151 = 151
  4. Calculate Protan G
    Protan G = 0.55833 * r + 0.44167 * g
    149 = 149

Engine last updated . Checked against 2 independently-derived tests how we verify calculators.

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