Tetradic Hue Rotation ±90°/180°
Named Tetradic angular hue-wheel construction (not RGB hue conversion, perceptual harmony or automated accent policy). Explicit declared color space/reference and caller applicability; not spectral equivalence, pigment mixing, press readiness or accessibility certification.
Description
A square tetradic hue scheme places four hues at quarter-circle intervals.
A square tetradic hue scheme places four hues at quarter-circle intervals.1
Rotating a hue does not select lightness, chroma, gamut or a usable print recipe. Use Tetradic Hue Rotation ±90°/180° to evaluate the supplied inputs under the model explained below.
When to use Tetradic Hue Rotation ±90°/180°
Use Tetradic Hue Rotation ±90°/180° to evaluate the supplied inputs under the model explained below. Choose the hue-space convention and confirm that the color has a meaningful chromatic hue.
How to use Tetradic Hue Rotation ±90°/180° and understand its results
- Choose the hue-space convention and confirm that the color has a meaningful chromatic hue.
- Enter Primary hue degrees, Caller hue defined using the field table and validation rules below, then run the tool.
- Read Harmony hue degrees, Hue evidence available; 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 |
|---|---|---|---|
| primaryHueDegrees | Primary hue degrees | number | Required; constraints below |
| callerHueDefined | Caller hue defined | boolean | Required; constraints below |
Enter a finite hue in degrees and true only when an independently meaningful chromatic hue is available. False is an input error; neutral-color hue is not invented. Add the offsets [90, 180, 270] in that order and wrap each result into [0,360). The output contains the additional hues, not the unchanged primary hue, and hueEvidenceAvailable is true on success. No hue-space conversion, lightness, chroma or gamut decision is made.
additionalHues = wrap360(primaryHue+offset) for offsets [90, 180, 270] Use the field order, units and branch conditions described above.
| Output field | Meaning | Value type |
|---|---|---|
| harmonyHueDegrees | Harmony hue degrees | array of number |
| hueEvidenceAvailable | Hue evidence available | boolean |
{
"input": {
"primaryHueDegrees": 350,
"callerHueDefined": true
},
"output": {
"harmonyHueDegrees": [
80,
170,
260
],
"hueEvidenceAvailable": true
}
}Limitations and assumptions
Rotating a hue does not select lightness, chroma, gamut or a usable print recipe. 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 Triadic Hue Rotation ±120° for a related task: A triadic hue scheme places two additional hues one third and two thirds around a color circle.
Use Complementary Hue Rotation 180° for a related task: A complementary hue sits half a rotation from the chosen hue.
References
-
Tetradic Hue Rotation ±90°/180° — tool.io
Similar or alternative tools
- Triadic Hue Rotation ±120°
A triadic hue scheme places two additional hues one third and two thirds around a color circle.
- Complementary Hue Rotation 180°
A complementary hue sits half a rotation from the chosen hue.