ForHosting KIT · Developer Utilities

Simulate protanomaly color

Protanomaly is a common form of anomalous trichromacy in which the long-wavelength (L) cones of the retina have reduced sensitivity to red light.

● BetaFree · in your browser

Run — free How it works & API

Use it from WebAPIEmailTelegramApp soon

Designers, accessibility auditors, and educators often need a quick, deterministic preview of how a brand color, chart series, or UI state might look when red discrimination is weakened—not full protanopia, but a partial blend between normal vision and a protan projection. This simulate protanomaly color tool accepts a hex or RGB color plus an optional severity from zero to one, converts the color into LMS cone space, partially applies a Viénot-style protan transform that rebuilds the L channel from M and S, converts back to RGB, and returns the simulated hex, channels, and CSS string. Severity zero leaves the color unchanged; severity one approximates full protanopia; the default of zero point six models a typical moderate protanomaly. The same pure algorithm powers the free browser widget and the API path, so design tokens and automated contrast checks never disagree on the filtered sample.

How to use it

Enter your values in the form above. The tool checks them before calculating and shows the result on the same page.

Check your inputs

Use the labels and units shown next to each field. If something is missing or outside the allowed range, the page points to the field to fix.

Use it again or automate it

Use the browser tool for individual checks and the API when you need the same capability in an automated workflow.

What you can do with it

Get an answer now

Enter one set of values and see the result without building a spreadsheet or script.

Compare scenarios

Change one value at a time and rerun the calculation to understand what affects the result.

Automate repeated work

Use the API when the same calculation needs to run inside your product or workflow.

FAQ

What is protanomaly and how is it simulated here?

Protanomaly is reduced L-cone (red) sensitivity. This tool maps RGB to LMS, rebuilds L from M and S as in a protan projection, blends with the original LMS by severity, and converts back to RGB.

What does the severity parameter do?

Severity is a blend weight in [0, 1]. 0 returns the original color; 1 applies full protanopia projection; the default 0.6 models a typical moderate protanomaly. Aliases: amount, strength, severity.

Which color formats are accepted?

Hex (#RGB or #RRGGBB), CSS rgb()/rgba(), bare r,g,b text, or separate r, g, b integers 0–255. Missing or invalid color fails with invalid_input.

Is this a medical or diagnostic test?

No. It is an engineering approximation for design and education previews, not a clinical assessment of color vision.

What does the protanomaly color simulator cost?

The browser tool is free. API requests use prepaid KIT balance at $0.002 per successful call; invalid input is not billed.

For developers — API access

Everything on this page is available programmatically. This section is for teams who want to wire it into their own systems; everyone else can just use the tool above.

API endpoint

POSThttps://api.kit.forhosting.com/color/sim-protanomaly

Prefer to automate it? One authenticated POST creates the task; the result comes back by webhook or a signed link. The same capability also runs here on the web, by email and from Telegram — and soon from our app too.

Call it from your stack

curl -X POST https://api.kit.forhosting.com/color/sim-protanomaly \
  -H "Authorization: Bearer $KIT_KEY" \
  -H "Content-Type: application/json" \
  -d '{"color":"#e74c3c","hex":"valor-ejemplo"}'

const res = await fetch("https://api.kit.forhosting.com/color/sim-protanomaly", {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${process.env.KIT_KEY}`,
    "Content-Type": "application/json"
  },
  body: JSON.stringify({
    "color": "#e74c3c",
    "hex": "valor-ejemplo"
  })
});
const { task_id } = await res.json();

import os, requests

res = requests.post(
    "https://api.kit.forhosting.com/color/sim-protanomaly",
    headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
    json={
    "color": "#e74c3c",
    "hex": "valor-ejemplo"
},
)
task_id = res.json()["task_id"]

<?php
$res = file_get_contents("https://api.kit.forhosting.com/color/sim-protanomaly", false, stream_context_create([
  "http" => [
    "method"  => "POST",
    "header"  => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
    "content" => '{"color":"#e74c3c","hex":"valor-ejemplo"}',
  ],
]));
$task = json_decode($res, true);

body := bytes.NewBufferString(`{"color":"#e74c3c","hex":"valor-ejemplo"}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/color/sim-protanomaly", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)

Example request

{
  "color": "#e74c3c",
  "hex": "valor-ejemplo"
}

Example response

{
  "task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
  "type": "color.sim_protanomaly",
  "status": "queued",
  "_links": {
    "result": "/tasks/tsk_…/result"
  }
}

The API is asynchronous: the call returns a task_id immediately and the result arrives by webhook. Polling is capped at 1 req/s per task.

Pricing

Per request$0.002

Published price — no tokens, no invented credits. A failed task is never charged.

Errors

HTTP	Code	Meaning
`401`	`unauthorized`	Missing or invalid API key.
`402`	`insufficient_balance`	Your balance doesn't cover the task price.
`404`	`unknown_type`	That task type doesn't exist.
`429`	`rate_limited`	Too many requests. Use the webhook instead of polling.

Read the full KIT documentation →