X11 Nearest Color Name Lookup

Nearest caller independently verified X11 name Lab palette, not CSS named-color alias or single nearest tie suppression. Explicit declared color space/reference and caller applicability; not spectral equivalence, pigment mixing, press readiness or accessibility certification.

Description

An X11 color-name match requires a particular palette and coordinate convention.

An X11 color-name match requires a particular palette and coordinate convention.^[1]

Nearest supplied Lab swatches do not imply an installed universal name list or an exact rendering match. Use X11 Nearest Color Name Lookup to find nearest supplied Lab swatches.

When to use X11 Nearest Color Name Lookup

Use X11 Nearest Color Name Lookup to find nearest supplied Lab swatches. Supply the intended palette IDs and Lab swatches under one common reference convention, then enter the query in that same coordinate system.

How to use X11 Nearest Color Name Lookup and understand its results

Supply the intended palette IDs and Lab swatches under one common reference convention, then enter the query in that same coordinate system.
Enter Caller verified x11 ids, Caller same white x11 lab swatches, Query same white lab using the field table and validation rules below, then run the tool.
Read Nearest caller ids, Minimum declared space distance; interpret the units, signs, ordering and unknown-value placeholders described below.
Correct reported input errors and rerun. Apply successful results according to their specific meanings and check the assumptions before using them in a decision.

Input field	Meaning	Value type	Requirement
callerVerifiedX11Ids	Caller verified x11 ids	array of string	Required; constraints below
callerSameWhiteX11LabSwatches	Caller same white x11 lab swatches	array of array	Required; constraints below
querySameWhiteLab	Query same white lab	array of number	Required; constraints below

Provide unique nonblank caller swatch IDs of at most 128 UTF-16 code units, one finite three-component Lab swatch per ID and a finite three-component query. The registry must be nonempty and all coordinates must use the same independently established white/reference convention. Calculate Euclidean distances and return every ID whose distance is exactly the minimum, preserving caller order. Ties use exact numeric equality. No named palette, RGB conversion, white adaptation or official matching certification is supplied.

nearest IDs = all caller IDs with distance==min(hypot(L−Lq,a−aq,b−bq))

Use the field order, units and branch conditions described above.

Output field	Meaning	Value type
nearestCallerIds	Nearest caller ids	array of string
minimumDeclaredSpaceDistance	Minimum declared space distance	number

json

{
  "input": {
    "callerVerifiedX11Ids": [
      "a",
      "b"
    ],
    "callerSameWhiteX11LabSwatches": [
      [
        50,
        0,
        0
      ],
      [
        50,
        3,
        4
      ]
    ],
    "querySameWhiteLab": [
      50,
      3,
      4
    ]
  },
  "output": {
    "nearestCallerIds": [
      "b"
    ],
    "minimumDeclaredSpaceDistance": 0
  }
}

Limitations and assumptions

Nearest supplied Lab swatches do not imply an installed universal name list or an exact rendering match. Apply the exact scope and assumptions explained above.

All listed fields require explicit values. Unexpected fields, incorrect types, nonfinite numbers and sparse arrays fail validation. Domain-specific bounds, alignments and supported tokens are explained above; extremely large inputs or outputs can also be rejected. Input errors differ from successful false results, empty match lists and unknown-evidence placeholders.

Alternative or Complementary methods

Use Tailwind Palette Nearest Shade Lookup for a related task: Tailwind shade matching depends on the supplied palette edition and color coordinates.

Use Pantone Nearest RGB Lookup for a related task: Pantone approximations need a particular reference and comparable swatch measurements.

References

X11 Nearest Color Name Lookup — tool.io

Similar or alternative tools

Tailwind Palette Nearest Shade Lookup
Tailwind shade matching depends on the supplied palette edition and color coordinates.
Pantone Nearest RGB Lookup
Pantone approximations need a particular reference and comparable swatch measurements.