Color Similarity Calculator API

GET

Check how closely two colors match with overall similarity scores and categories.

Color Similarity Calculator measures color similarity between two hex values. It returns an overall similarity score, a categorical match rating, and RGB and HSL channel breakdowns, while paid plans add Delta E and color distance metrics.

Try it — live request, no key required

Request

GETapi.apiverve.com/v1/colorsimilarity?color1=FF5733&color2=FF6B47

Query parameters

color1string

color2string

Verification

Format

No key required to try it. Get a key to use it in your app.

Example

{
  "status": "ok",
  "error": null,
  "data": {
    "color1": {
      "hex": "#FF5733",
      "rgb": {
        "r": 255,
        "g": 87,
        "b": 51
      },
      "hsl": {
        "h": 10.6,
        "s": 100,
        "l": 60
      }
    },
    "color2": {
      "hex": "#FF6B47",
      "rgb": {
        "r": 255,
        "g": 107,
        "b": 71
      },
      "hsl": {
        "h": 11.7,
        "s": 100,
        "l": 63.9
      }
    },
    "rgb_distance": 28.28,
    "rgb_similarity": 93.6,
    "hsl_similarity": 97.71,
    "overall_similarity": 95.65,
    "delta_e": 10.61,
    "hue_difference": 1.15,
    "saturation_difference": 0,
    "lightness_difference": 3.92,
    "similarity_category": "nearly identical",
    "are_identical": false
  }
}

About the Color Similarity Calculator API

Color Similarity Calculator works by converting hex colors to RGB and HSL, calculating Euclidean distance in color space, and comparing hue, saturation, and lightness differences for comprehensive similarity analysis.

What people use it for

Color Matching: Find and compare similar colors for design consistency and brand compliance
Image Processing: Compare colors in images for color correction and matching operations
Design Systems: Validate color palette consistency and identify similar colors in design systems
Quality Control: Compare product colors against standards for quality assurance and brand consistency

Ways to call it

One endpoint, many ways in — REST with JSON, XML, YAML and CSV, plus GraphQL and an MCP interface for AI agents.

JSON: Default REST response
XML: Markup format
YAML: Human-readable
CSV: Tabular export
GraphQL: Query language
MCP: For AI agents

View all integrations →

Other ways to use Color Similarity Calculator

Same data, same APIVerve account, same credit balance — one key works on all of them.

Give it to an AI agentConnect over MCP and your agent calls it as a native tool — Claude, Cursor, ChatGPT.on VerveKit Google Sheets or ExcelA =VERVE() formula fills a column — no script, no export, recalculates in place.on VerveSheets Ground an agent on itA cited, machine-checkable fact your model can't produce on its own.on VerveContext

Questions.

Common questions about the Color Similarity Calculator API.

Read the docs →

What color formats can I pass into the calculator?

You can submit any standard hex color code, formatted either with or without a leading hash symbol. The API accepts both inputs and converts them into RGB and HSL coordinates before running the comparison algorithms.

Which comparison metrics and algorithms does the calculation use?

Color Similarity Calculator evaluates color pairs using Euclidean distance in RGB color space, HSL comparison across hue, saturation, and lightness, and Delta E for perceptual difference. It also outputs an overall combined similarity percentage and a descriptive similarity category.

Are Delta E and individual channel differences included on the Free plan?

No. The Free plan provides the overall similarity percentage, the similarity category, whether the colors are identical, and converted RGB and HSL values. Detailed breakdown metrics, including Delta E, RGB distance, RGB similarity, HSL similarity, and separate hue, saturation, and lightness differences, require any paid plan.

What would 25,000 color comparisons a month cost me?

Running 25,000 comparisons uses 50,000 credits, taking up one quarter of the 200,000 credits included in the Starter plan. On Starter, comparisons work out to about $0.30 per 1,000 calls, or $0.0003 per call. You can also test with 100 free comparisons every month.

How does the API report an exact color match?

When two identical colors are evaluated, the response sets the are_identical flag to true and reports an overall similarity score of 100 percent. On paid plans, the individual difference fields, such as hue, saturation, lightness, and RGB distance, evaluate to zero.

Request parameters — GET /v1/colorsimilarity

Sent in the query string. Premium parameters are accepted on every plan but only take effect on plans that include them. Anything not listed here is dropped rather than passed through.

Required

Parameter	Type	Example	Description
`color1`Required	string	`FF5733`	First hex color value (with or without # prefix) hexColor
`color2`Required	string	`FF6B47`	Second hex color value (with or without # prefix) hexColor

Example request

1
2

curl "https://api.apiverve.com/v1/colorsimilarity?color1=FF5733&color2=FF6B47" \
  -H "x-api-key: YOUR_API_KEY"

Authentication

Send your key in the x-api-key header. That is the only auth step — no token exchange, and no per-endpoint scope to configure.

Header	When	Value
`x-api-key`Required	Every request	Your API key. Header names are case-insensitive, so `X-API-Key` is the same header.
`Authorization`Alternate	Instead of the above	`Bearer <key>` — for clients that only expose bearer auth. Resolves to the same account and the same billing.

401 is the only auth verdict

A 401 means the key is missing, invalid or expired. A 403 means the key is valid but not permitted here — blocked by a key restriction or an IP allow-list. Running out of credits is a 429.

Response — GET /v1/colorsimilarity

Every APIVerve endpoint returns the same three top-level keys, so one response handler covers your whole integration: status, error and data. Only data changes shape.

Sample response

{
  "status": "ok",
  "error": null,
  "data": {
    "color1": {
      "hex": "#FF5733",
      "rgb": {
        "r": 255,
        "g": 87,
        "b": 51
      },
      "hsl": {
        "h": 10.6,
        "s": 100,
        "l": 60
      }
    },
    "color2": {
      "hex": "#FF6B47",
      "rgb": {
        "r": 255,
        "g": 107,
        "b": 71
      },
      "hsl": {
        "h": 11.7,
        "s": 100,
        "l": 63.9
      }
    },
    "rgb_distance": 28.28,
    "rgb_similarity": 93.6,
    "hsl_similarity": 97.71,
    "overall_similarity": 95.65,
    "delta_e": 28.28,
    "hue_difference": 1.15,
    "saturation_difference": 0,
    "lightness_difference": 3.92,
    "similarity_category": "nearly identical",
    "are_identical": false
  }
}

Response fields

Paths are relative to data. Premium fields are absent rather than zeroed on plans that do not include them, so check for presence instead of comparing to 0.

Field	Type	Example	Description
`color1`	object	`{...}`	The first colour, in hex, RGB and HSL
`hex`	string	`"#FF5733"`	First color in hexadecimal format representation
`rgb`	object	`{...}`	First colour as red, green and blue channels
`r`	number	`255`	Red channel value for first color
`g`	number	`87`	Green channel value for first color
`b`	number	`51`	Blue channel value for first color
`hsl`	object	`{...}`	First colour as hue, saturation and lightness
`h`	number	`10.6`	Hue value for first color in degrees
`s`	number	`100`	Saturation percentage for first color
`l`	number	`60`	Lightness percentage for first color
`color2`	object	`{...}`	The second colour, in hex, RGB and HSL
`hex`	string	`"#FF6B47"`	Second color in hexadecimal format representation
`rgb`	object	`{...}`	Second colour as red, green and blue channels
`r`	number	`255`	Red channel value for second color
`g`	number	`107`	Green channel value for second color
`b`	number	`71`	Blue channel value for second color
`hsl`	object	`{...}`	Second colour as hue, saturation and lightness
`h`	number	`11.7`	Hue value for second color in degrees
`s`	number	`100`	Saturation percentage for second color
`l`	number	`63.9`	Lightness percentage for second color
`rgb_distance`Premium	number	`28.28`	Euclidean distance between colors in RGB space
`rgb_similarity`Premium	number	`93.6`	Percentage similarity based on RGB color space
`hsl_similarity`Premium	number	`97.71`	Percentage similarity based on HSL color space
`overall_similarity`	number	`95.65`	Combined similarity percentage from all algorithms
`delta_e`Premium	number	`28.28`	Delta E color difference metric for perceptual similarity
`hue_difference`Premium	number	`1.15`	Hue difference between colors in degrees
`saturation_difference`Premium	number	`0`	Saturation percentage difference between colors
`lightness_difference`Premium	number	`3.92`	Lightness percentage difference between colors
`similarity_category`	string	`"nearly identical"`	Human readable category describing similarity level
`are_identical`	boolean	`false`	Boolean indicating if colors are exactly identical

Response headers

Every response carries your balance, so your own code always knows where it stands without polling anything. All four are exposed to browsers through CORS.

Header	What it carries
`x-api-remaining-credits`	Credits left in the current cycle
`x-api-credits-used`	Credits spent in the current cycle
`x-api-max-credits`	The allowance for the cycle
`x-api-version`	Version of the endpoint that answered

Errors

Read the HTTP status first, then error for the specific reason. The body names the parameter that has to change.

Status	Meaning	What to do
`400`	Input was rejected	Read `error`; it names the parameter that has to change.
`401`	Key missing or invalid	Check the header name and the key value.
`403`	Key valid, but not permitted here	A key restriction or an IP allow-list — never a bad key.
`429`	Rate limited, or out of credits	Read `error` to tell them apart, then back off or top up.

What a call costs — 2 credits per call

Credits are shared across every APIVerve API — one balance, one key, one bill. Failed requests never count against it, so a rejected input costs nothing.

Plan	Per month	Credits	Color Similarity Calculator calls	Per 1,000 calls
Free	Free	200	100	Free
Starter	$29.99	200,000	100,000	$0.30
Pro	$99.99	1,000,000	500,000	$0.20
Mega	$299.99	4,000,000	2,000,000	$0.15

Calls are what the credits buy at this API's rate — spend them here, on any of the other APIs, or across both. Nothing is reserved per endpoint.

Compare all pricing tiers →

Call it from cURL — GET /v1/colorsimilarity

No SDK to install — this is a plain HTTPS call to /v1/colorsimilarity with your key in the x-api-key header. Swap in a real key and it runs as-is.

cURL

1
2

curl "https://api.apiverve.com/v1/colorsimilarity" \
  -H "x-api-key: YOUR_API_KEY"

Resources

GitHubapiverve/colorsimilarity-apiSource, issues and the examples this page is built from.ReferenceColor Similarity Calculator API docsEvery parameter, every response field, and the errors.ParametersWhat this call acceptsRequired and optional inputs, with example values.

Also published for

@apiverve/colorsimilaritynpm APIVerve.API.ColorSimilarityCalculatorNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from Node.js — GET /v1/colorsimilarity

Install the Node.js SDK, then call the Color Similarity Calculator API with your key. The client wraps the same HTTPS request, so anything it returns is what the endpoint returns.

Install — npm

npm install @apiverve/colorsimilarity

Node.js

const res = await fetch("https://api.apiverve.com/v1/colorsimilarity", {
  headers: { "x-api-key": "YOUR_API_KEY" },
});
const { data } = await res.json();
console.log(data);

Resources

npm@apiverve/colorsimilarityThe published Node.js client, versioned and signed.GitHubapiverve/colorsimilarity-apiSource, issues and the examples this page is built from.ReferenceColor Similarity Calculator API docsEvery parameter, every response field, and the errors.ParametersWhat this call acceptsRequired and optional inputs, with example values.

Also published for

APIVerve.API.ColorSimilarityCalculatorNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from Python — GET /v1/colorsimilarity

No SDK to install — this is a plain HTTPS call to /v1/colorsimilarity with your key in the x-api-key header. Swap in a real key and it runs as-is.

Python

import requests

res = requests.get(
    "https://api.apiverve.com/v1/colorsimilarity",
    headers={"x-api-key": "YOUR_API_KEY"},
)
print(res.json()["data"])

Resources

Also published for

@apiverve/colorsimilaritynpm APIVerve.API.ColorSimilarityCalculatorNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from C# / .NET — GET /v1/colorsimilarity

Install the C# / .NET SDK, then call the Color Similarity Calculator API with your key. The client wraps the same HTTPS request, so anything it returns is what the endpoint returns.

Install — NuGet

dotnet add package APIVerve.API.ColorSimilarityCalculator

C# / .NET

using var client = new HttpClient();
client.DefaultRequestHeaders.Add("x-api-key", "YOUR_API_KEY");

var json = await client.GetStringAsync("https://api.apiverve.com/v1/colorsimilarity");
Console.WriteLine(json);

Resources

NuGetAPIVerve.API.ColorSimilarityCalculatorThe published C# / .NET client, versioned and signed.GitHubapiverve/colorsimilarity-apiSource, issues and the examples this page is built from.ReferenceColor Similarity Calculator API docsEvery parameter, every response field, and the errors.ParametersWhat this call acceptsRequired and optional inputs, with example values.

Also published for

@apiverve/colorsimilaritynpm

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from Go — GET /v1/colorsimilarity

No SDK to install — this is a plain HTTPS call to /v1/colorsimilarity with your key in the x-api-key header. Swap in a real key and it runs as-is.

req, _ := http.NewRequest("GET", "https://api.apiverve.com/v1/colorsimilarity", nil)
req.Header.Set("x-api-key", "YOUR_API_KEY")

res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))

Resources

Also published for

@apiverve/colorsimilaritynpm APIVerve.API.ColorSimilarityCalculatorNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from PHP — GET /v1/colorsimilarity

No SDK to install — this is a plain HTTPS call to /v1/colorsimilarity with your key in the x-api-key header. Swap in a real key and it runs as-is.

PHP

$ch = curl_init("https://api.apiverve.com/v1/colorsimilarity");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, ["x-api-key: YOUR_API_KEY"]);

$response = curl_exec($ch);
echo $response;

Resources

Also published for

@apiverve/colorsimilaritynpm APIVerve.API.ColorSimilarityCalculatorNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from Ruby — GET /v1/colorsimilarity

No SDK to install — this is a plain HTTPS call to /v1/colorsimilarity with your key in the x-api-key header. Swap in a real key and it runs as-is.

Ruby

require "net/http"

uri = URI("https://api.apiverve.com/v1/colorsimilarity")
req = Net::HTTP::Get.new(uri)
req["x-api-key"] = "YOUR_API_KEY"

res = Net::HTTP.start(uri.hostname, uri.port, use_ssl: true) { |h| h.request(req) }
puts res.body

Resources

Also published for

@apiverve/colorsimilaritynpm APIVerve.API.ColorSimilarityCalculatorNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

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Color Similarity Calculator API

Try it — live request, no key required

About the Color Similarity Calculator API

What people use it for

Ways to call it

Other ways to use Color Similarity Calculator

Questions.

Request parameters — GET /v1/colorsimilarity

Required

Authentication

Response — GET /v1/colorsimilarity

Response fields

Response headers

Errors

What a call costs — 2 credits per call

Call it from cURL — GET /v1/colorsimilarity

Resources

Also published for

Call it from Node.js — GET /v1/colorsimilarity

Resources

Also published for

Call it from Python — GET /v1/colorsimilarity

Resources

Also published for

Call it from C# / .NET — GET /v1/colorsimilarity

Resources

Also published for

Call it from Go — GET /v1/colorsimilarity

Resources

Also published for

Call it from PHP — GET /v1/colorsimilarity

Resources

Also published for

Call it from Ruby — GET /v1/colorsimilarity

Resources

Also published for

Zero-code embed — one snippet, no backend

Changelog — Color Similarity Calculator API

Math/Calculations

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