Reference Lock Before Recipe Claim
An atlas-only workflow for spectral color targeting from external color requests.
1. Abstract
Color development often begins with an external request: an image, a brand color, a HEX value, a Lab value, a palette reference, or a named spot-color description. In conventional workflows, these inputs are frequently treated as color targets directly. ARBE takes a different position.
In the ARBE AtlasFit workflow, external color inputs are not final identities. They are requests. A valid color identity exists only after deterministic routing into a locked Atlas reference of the form Hxxx_Lxxx_Cxxx.
From there, a recipe is generated only as a candidate. The candidate curve is evaluated against the Atlas reference. Reference Lock validates the candidate. The Metamerism Gate qualifies the lock.
This whitepaper presents an atlas-only workflow using the case H275_L030_C045, routed from an image sample into a spectral recipe candidate and validated through AtlasFit, Spectral Scissor, and Metamerism Gate.
2. Method Workflow
The mandatory ARBE workflow is strictly sequential. It prevents the system from confusing initial suggestions with validated spectral targets.
2.1 Workflow Rules
No recipe or Scissor claim may be made before Atlas binding.
The final AtlasFit evaluation must be performed against the Master PKL reference space.
External values must be routed deterministically to exactly one Master-PKL Atlas reference.
Only an Hxxx_Lxxx_Cxxx reference is a valid ARBE color identity.
3. Case Study: Image Sample to H275_L030_C045
To demonstrate the method, a saturated blue region extracted from an image sample was processed. The image itself was treated strictly as an external request, not as a color identity.
3.1 Original Image-Derived Request
RGB 6, 69, 138 HEX #06458A Lab 29.024, 4.543, -45.352
3.2 Atlas Binding
ATLAS_BOUND
Atlas Binding: H275_L030_C045
ΔE00: 0.796918
The bound Atlas reference profile contains the following deterministic data:
FP::H275_L030_C045
H275::L030::C045
LabL_30.000::a+3.922::b-44.829
λV2_418.441
λEE_510.113
Δλ_-91.672
HEX_#08488E
RGB_8_72_142
This profile represents the locked ARBE Atlas identity for the request.
4. Recipe Candidate
Following Atlas binding, an initial spectral recipe candidate was generated:
| Component | Share |
|---|---|
| PB28 | 65.833% |
| PB36 Maimeri Brera | 26.458% |
| PB15:3 Maimeri Brera (Iridescent Blue) | 7.708% |
4.1 Candidate Color Metrics
L: 30.330
a: 3.943
b: -44.397
4.2 Spectral RMSE
vs Scissored Target Curve: 0.0183136
vs Master Target Curve: 0.0329856
4.3 Lab Proximity Delta
| Metric | L | a | b |
|---|---|---|---|
| Target Lab | 30.000 | 3.922 | -44.829 |
| Candidate Lab | 30.330 | 3.943 | -44.397 |
| Delta | +0.330 | +0.021 | +0.432 |
The numerical proximity is close, but the recipe remains a candidate until validated by the curve.
5. AtlasFit Result
AtlasFit evaluates the candidate curve against the Master PKL reference space.
Nearest Reference: H275_L030_C045
Target Reference: H275_L030_C045
Target Rank: 1
Lock Status: REFERENCE_LOCKED
Nearest ΔE00: 0.312976
5.1 Validation Rule
The candidate locks back to the same Atlas reference established from the external request. To achieve REFERENCE_LOCKED, the nearest reference must equal the target reference, and the target rank must be exactly 1.
6. Scissor Boundary Check
The Scissor step evaluates whether the candidate curve remains structurally controlled after crossing removal and reference retention.
| Observed Scissor Result | Value |
|---|---|
| Crossings Before / After | 6 → 0 |
| Nearest Reference After Correction | H275_L030_C045 |
| ΔE00 to Target | 0.201633 |
| λ* drift / ΔΔλ* | +5.143656 nm |
| Scissor Status | SCISSOR_UNLOCKED |
6.2 Analysis of Boundary Warning
The Scissor correction successfully removed all crossings, and the nearest reference remained correct. However, because the λ* drift exceeded the 5.000000 nm gate limit, the status is flagged as SCISSOR_UNLOCKED.
This is not a failure of the workflow. It is an expected boundary warning. ARBE reports boundary conditions transparently to ensure structural control.
7. Metamerism Gate
Following Reference Lock, the Metamerism Gate evaluates the target and candidate curves under five proxy illuminant conditions. The Metamerism Gate uses proxy illuminants for technical screening.
| Illuminant Condition | Observed Color Difference |
|---|---|
| D50 | ΔE76 1.386376 |
| D65 | ΔE76 1.316672 |
| A | ΔE76 1.538952 |
| TL84/F11 | ΔE76 1.165988 |
| LED 4000K | ΔE76 1.814561 |
REFERENCE_LOCKED_METAMERISM_LOW
8. Claim Boundary
ARBE does not claim
- replacement of third-party color systems
- exact spot-color equivalence
- certified third-party matching
- production approval
- visual identity equivalence
- generated or AI-designed color
ARBE claims only
- deterministic routing of external color requests into Atlas references
- candidate recipe evaluation by spectral curve
- Reference Lock against the Master PKL
- Metamerism qualification after lock
ARBE does not replace third-party color systems. ARBE converts external color requests into reference-locked spectral targets.
9. Startup Relevance
A named color catalogue can describe a request.
An image can describe a request.
A HEX value can describe a request.
A brand color can describe a request.
ARBE does not treat any of them as final identity.
The valid identity begins only after routing into:
Hxxx_Lxxx_Cxxx
This strict distinction eliminates communication ambiguities between early-stage product teams, digital designers, and industrial material manufacturing partners.
10. Glossary
Hxxx_Lxxx_Cxxx
The standardized ARBE Atlas reference notation representing Hue, Lightness, and Chroma coordinates within a controlled, discrete color space.
Master PKL
The locked spectral lookup database that serves as the definitive reference space for ARBE routing and validation steps.
AtlasFit
The analytical engine that tests candidate recipe curves back against the Master PKL to see whether they index to the correct target coordinate.
Reference Lock
A verified system state achieved when a recipe candidate’s nearest match equals the target reference and ranks as the number one choice.
Spectral Scissor
A mandatory processing step designed to remove wave crossings and monitor structural drift.
Boundary Warning
A system state, such as SCISSOR_UNLOCKED, indicating that the color reference remains correct, but a physical property such as λ* drift has crossed a safety gate limit.
Metamerism Gate
A multi-illuminant consistency test checking stability under D50, D65, A, TL84/F11, and LED 4000K proxy illuminants to assess technical color variance.
11. Reproducibility Metadata
| Framework Documentation | ARBE AtlasFit MixLock KB v0.5 |
|---|---|
| Reference Atlas File | atlas_master__active_master__v2_illumext.pkl |
| Atlas Record Count | 13283 Atlas records |
| Spectral Resolution | 36 spectral bands |
| Core Solver Environment | Brent optimization model for λ*_V2 value sets |
| Target Coordinates | H275_L030_C045 |
| Scissor Gate Limit | 5.000000 nm |
| Verification Timestamp | 2026-06-27 09:10 UTC |
Final Process Verdict
Target Atlas Reference: H275_L030_C045
Recipe Candidate: PB28 / PB36 / PB15:3
AtlasFit Status: REFERENCE_LOCKED
Scissor Status: SCISSOR_UNLOCKED
Boundary Warning: λ* drift exceeded 5.0 nm gate
Metamerism Status: LOW
Final System Status: REFERENCE_LOCKED_METAMERISM_LOW
The workflow establishes a reference-locked spectral target within the ARBE Atlas space by proving that external impressions and initial recipe proposals are distinct from a reference-locked identity.
The recipe is the candidate.
The curve decides.
The reference lock makes it valid.
The metamerism gate qualifies the lock.