Perceptual difference — ΔE00
ΔE2000 between the on-screen renderings. Below ~1 is imperceptible to most viewers; 1–2 noticeable on close comparison; above ~5 plainly different colours. These are distances between approximations, not between measured samples — useful for ranking, not for tolerance decisions.
This sheet is not a colour proof. RAL, Pantone and 日塗工 are physical standards defined by measured colour; every digital equivalent here is an approximation, and saturated colours fall outside CMYK gamut entirely. No printer in reach is ICC-calibrated to a proofing standard, and paper white is not coated steel. Use the print for relative judgement against your physical samples — never to accept or reject a finish. For that, hold a RAL K7 fan deck against the actual piece.
Where the numbers come from
RAL Classic — 213 colours, hex from the standard published table, cross-checked on ten values against an independent source.
日塗工 JPMA — 666 chips with their published Munsell notation and RGB. Hex is derived from the RGB triplets, because the source's printed hex column contradicts its own RGB on several rows.
Pantone — published approximations only, and unofficial. The modern four-digit codes (2462C and similar) are not in this set; where the EXPO preset names one, the colour comes from the EXPO's own CMYK, not from a Pantone lookup.
Munsell and the chroma check
Where a colour carries a published Munsell value, that value governs and the check uses it.
Otherwise Munsell is read from the nearest 日塗工 chip and shown with its ΔE. A large ΔE means the reading is unreliable, and the check says so rather than ruling.
The chroma limit is yours to set and is off by default. Landscape and signage ordinances often cap chroma to keep colours from competing with their surroundings; the ceiling varies by authority, so the tool takes a number rather than assuming one.
The tool reports the figure and nothing more. It does not know which rule applies to your project, whether that rule covers the surface you are testing, or whether the authority reads it the way you do. Confirm a boundary case with whoever approves the work.
The PDF
Written in the page with pdf-lib and filled in DeviceCMYK — the ink percentages are in the file, not left to a print driver. Same set, same numbers, every export.
An .icc is optional. It adds an output intent, which declares what those numbers mean colorimetrically for a RIP or a soft proof. It never changes the ink values. Without one the PDF is still correct DeviceCMYK.
Profiles are remembered, not shipped. Add one and it stays in this browser; pick it from the list next time. No profile travels with this page, because CMYK press profiles carry redistribution terms — Adobe's Japan Color licence forbids bundling, and ECI require written permission. Load your own, which is the correct one anyway: the right output intent depends on your printer, not on whoever built this.
Standard PDF fonts cannot set Japanese, so the sheet romanises any Japanese text. Everything on it is otherwise verbatim.