Add objective O6 and criterion SC8 to the Business Case: visible colours

Drawing the first painting from a photograph showed colours that pass the
white-shade rule (SC3) but are still faint on the white background. Add O6
(every dot clearly visible: drop palette colours whose contrast with white is
below 2.0) and SC8, plus the WCAG contrast standard, an In Scope item, a risk
row and the Problem Statement sentence. SC3 is unchanged and still holds.

The limit of 2.0 was chosen by S01 from the measured palette of the reference
image: 8 of its 30 colours fall below it and the next is at 2.56, so 22 remain.

Record the delta re-review as RC-007 (verdict Go, terms confirmed by S01).

docs/artifact-registry.md

@@ -15,7 +15,7 @@ document of a type. `Primary File` may contain a glob (e.g.
 | SA | Stakeholder Analysis | docs/stakeholder-analysis.md | 002 |
 | PP | Project Plan | docs/project-plan.md | 002 |
 | MIL | Milestone / Gateway | docs/milestones/*.md | 003 |
-| RC | SQA Review Record | docs/sqa/reviews/rc-*.md | 007 |
+| RC | SQA Review Record | docs/sqa/reviews/rc-*.md | 008 |
 
 ## Languages
 

docs/business-case.md

@@ -11,7 +11,8 @@
 ## Version History
 | Date | Status | Author | Reviewer | Change | Commit |
 | --- | --- | --- | --- | --- | --- |
-| 2026-10-07 | Accepted | Jens Tirsvad Nielsen | S01 | Initial version | [b823d1f] |
+| 2026-10-07 | Deprecated | Jens Tirsvad Nielsen | S01 | Initial version | [b823d1f] |
+| 2026-10-08 | Accepted | Jens Tirsvad Nielsen | S01 | Added objective O6 and criterion SC8 (every dot clearly visible), the contrast standard, and a risk | pending |
 
 ---
 
@@ -35,6 +36,9 @@ proceed.
 - **Quality standards:** every quality criterion is tagged with an ISO/IEC
   25010:2023 characteristic. The code is reviewed against `qc-programming-python`
   before the pull request.
+- **Contrast:** the contrast ratio of the Web Content Accessibility Guidelines
+  (WCAG) 2.x, computed from relative luminance: 1.0 for a colour identical to
+  white and 21.0 for black.
 - **Source requirements:** the course lecture "The Hirst Painting Project
   Part 2 - Drawing the Dots" (a written summary of the lecture is the only
   source supplied; the reference image is not).
@@ -46,6 +50,8 @@ Without one, the loops, the `turtle` positioning logic and the colour handling
 taught in the lecture stay theory. The lecture itself names the usual
 failures: a visible trail between dots, a missing last dot, white shades in
 the palette that make dots invisible, and a slow, visibly drawing turtle.
+Drawing the first painting from a photograph showed one more: faint colours
+that pass the white-shade rule but still hardly show on the white background.
 
 ## Business Opportunity
 
@@ -63,6 +69,7 @@ so the effort the framework adds can be judged against the size of the work.
 | O3 | Colour every dot by a random choice from that palette. |
 | O4 | Keep the finished painting on screen until the user clicks, and present it cleanly: turtle hidden, no trail between dots. |
 | O5 | Deliver the work through the framework: plan and issues first, then code reviewed against `qc-programming-python` (`RC-*` verdict `Go`) before the pull request. |
+| O6 | Keep every dot clearly visible on the white background: drop palette colours whose contrast with white is below 2.0. |
 
 ## Scope
 
@@ -70,6 +77,7 @@ so the effort the framework adds can be judged against the size of the work.
 
 - One Python program using the standard `turtle` module, the `random` module and the `colorgram` library.
 - Extraction of the palette from one reference image, with white shades removed.
+- Removal of faint colours from the palette: colours whose contrast with white is below 2.0.
 - Drawing of the 10 by 10 dot grid: dot size, spacing, row change and heading handling.
 - Screen handling: `exitonclick`, hiding the turtle, pen up between dots, drawing speed.
 - The framework documents the plan-first workflow requires for this work (Business Case, Stakeholder Analysis, Project Plan, milestones), and the review records for them and for the code.
@@ -86,7 +94,7 @@ so the effort the framework adds can be judged against the size of the work.
 
 ### Tangible Benefits
 
-- A working program that produces the painting described in O1 to O4.
+- A working program that produces the painting described in O1 to O4, with every dot clearly visible (O6).
 - A reviewed codebase with a recorded review (`RC-*`) against the Python checklist.
 - A traceable record from objective to milestone to issue to code.
 
@@ -112,6 +120,7 @@ framework that the repository is built on.
 | SC5 | Clean result (O4) | Turtle hidden at the end; no line drawn between dots; window stays open until a click | Visual check of one full run |
 | SC6 | Run time (O4) | The full painting is drawn in 30 seconds or less | Timed run on the developer machine (value confirmed by S01) |
 | SC7 | Review gate (O5) | `RC-*` for the code has verdict `Go`; the pull request closes every issue it completes | Review record and pull request description |
+| SC8 | Visible colours (O6) | 0 palette colours with a contrast ratio against white below 2.0; SC3 still holds for the final palette (at least 2 colours) | Print of the extracted palette with the contrast of every colour, checked against the limit (value chosen by S01) |
 
 ## Risks
 
@@ -121,6 +130,7 @@ framework that the repository is built on.
 | `colorgram` or the `turtle` graphical toolkit (Tk) cannot be installed or does not run on the developer machine | The program cannot be run or checked | Check both in the first task of the palette phase, before any other work depends on them |
 | White or near-white shades stay in the palette | Dots are invisible on the white background, so SC1 looks failed | SC3 sets an explicit threshold and is checked on the printed palette |
 | Off-by-one errors: last dot of a row or the last row missing, or a trail drawn | SC1 or SC5 fails | SC1 counts the dots and SC5 checks for a trail; both are verified in the code review |
+| The contrast cut-off removes too many colours | The painting looks dull | The limit of 2.0 sits in a gap in the palette of the reference image: 8 of its 30 colours fall below it, and the palest colour kept has a contrast of 2.56, so 22 remain. SC3 still requires at least 2, and S01 judges the picture in the timed run |
 | Framework process outweighs the size of the work | Schedule slips and the exercise stops being a small one | Keep to two phases and plain tasks; no use cases or design artifacts (see Out of Scope) |
 | The only named reviewer is also the author | Reviews are not independent, as the review process requires | S01 accepted a documented self-review on 2026-10-07; each review record states it |
 
@@ -158,7 +168,7 @@ Roles, power and interest are in [SA-001]; they are not repeated here.
 
 | Stakeholder ID (SA) | Interest in this project |
 | --- | --- |
-| S01 | Owner of all objectives (O1 to O5); accepts the work and answers the open questions above |
+| S01 | Owner of all objectives (O1 to O6); accepts the work and answers the open questions above |
 
 ## Recommendation
 

docs/sqa/reviews/rc-007-business-case-visible-colours.md

@@ -0,0 +1,68 @@
+# Review Record: Business Case BC-001, objective O6 (delta)
+
+## Metadata
+| Key | Value |
+| --- | --- |
+| ID | RC-007 |
+| CrossReference | [BC-001], [RC-001], [SA-001], [QC-BC-001], [QC-LANG-001] |
+
+## Version History
+| Date | Status | Author | Reviewer | Change | Commit |
+| --- | --- | --- | --- | --- | --- |
+| 2026-10-08 | Accepted | Jens Tirsvad Nielsen | S01 | Initial version (draft prepared by the assistant for S01 to confirm)<br>Terms confirmed by S01, verdict `Go` | pending |
+
+---
+
+## Artifact Under Review
+
+- Instance reviewed: [BC-001], the revision of 2026-10-08 (second row of its Version History)
+- Checklist used: [QC-BC-001], together with [QC-LANG-001] because the Business Case is written in the PO language
+- Scope: delta re-review of criteria 2, 3, 4, 5 and 6 of [QC-BC-001] and criteria 3, 4, 5, 9 and 10 of [QC-LANG-001]. Reason: the revision adds objective O6, success criterion SC8, a scope item, a risk row, the contrast standard (WCAG) and a sentence in the Problem Statement, and it changes the Stakeholders row from "O1 to O5" to "O1 to O6". Earlier record: [RC-001], which passed every criterion on the first version. The other criteria are untouched by the revision and keep their earlier result: [QC-BC-001] 1 (cost-benefit), 7 (assumptions and constraints) and 8 (recommendation), and [QC-LANG-001] 1, 2, 6, 7 and 8 (metadata, headings, no translated twin, no change of language)
+- Language and domain: en / it (the artifact's Metadata rows)
+- Language reviewer: none. S01 reads English and knows the IT domain. S01 is also the author; S01 accepted a documented self-review on 2026-10-07 (see [RC-001], Action Item 1)
+
+**Status of this record:** final. The assistant read the revised Business
+Case against the criteria above; S01 confirmed the open point on 2026-10-08
+and the verdict is `Go`.
+
+**Stakeholder Analysis:** [SA-001] is not revised. S01's concern "The result looks clean and the window stays open until a click" (Usability) already covers O6, and every concern still traces to an objective, so its own checklist result is unchanged.
+
+**Evidence for SC8 and the risk row:** the palette of the reference image was measured on 2026-10-08 with the WCAG contrast ratio against white. The 30 colours range from 1.22 to 15.85; the eight palest lie between 1.22 and 1.96, the next colour is at 2.56, so a limit of 2.0 removes 8 and keeps 22. The limit was chosen by S01 on 2026-10-08.
+
+## Checklist Results
+
+| # | Criterion | Status | Evidence/Notes |
+| --- | --- | --- | --- |
+| 2 | Risks are identified with documented impact and mitigation | Pass | The Risks table now has 7 rows; the new row (the contrast cut-off removes too many colours) has the impact "The painting looks dull" and a mitigation with figures from the measurement above |
+| 3 | Success criteria are measurable, stating explicit targets rather than vague aspirations | Pass | SC8 states a target (0 palette colours with a contrast ratio against white below 2.0) and a measure (the printed palette with the contrast of every colour). It is consistent with SC3, which still holds for the final palette |
+| 4 | Scope explicitly separates In Scope vs Out of Scope | Pass | The new In Scope item names the faint-colour removal and its limit; Out of Scope is unchanged and still distinct (no other parameters, no interface, no packaging) |
+| 5 | Stakeholders are cross-referenced to Stakeholder Analysis IDs rather than re-described inline | Pass | The Stakeholders table still cites S01 only, now for "O1 to O6"; the new text refers to S01 by ID |
+| 6 | Methodology and quality-standard foundation are stated explicitly (e.g. ISO/IEC 25010, Larman) | Pass | The Methodological and Standards Foundation gains a "Contrast" bullet naming the WCAG 2.x contrast ratio computed from relative luminance, with its two reference values (1.0 for white, 21.0 for black) |
+
+## Language and Domain Results
+
+| # | Criterion | Status | Evidence/Notes |
+| --- | --- | --- | --- |
+| 3 | The content (prose and table cells) is written in the stated language | Pass | The new prose and table cells are English |
+| 4 | The register matches the one the registry gives for the artifact type | Pass | Registry gives IT Executive English for BC. The new objective, criterion and risk state decisions and targets; the technical definition (relative luminance) is confined to the standards bullet where a standard belongs |
+| 5 | Domain terms are the PO terms of the domain's dictionary, with no synonyms | Pass | S01 confirmed on 2026-10-07 that no dictionary is needed. The new term *faint colour* is used in every new place (Problem Statement, In Scope, Risks) and is defined by SC8 as a contrast below 2.0; *white shade* keeps its meaning from SC3 |
+| 9 | A reviewer competent in the domain, and in the language, has confirmed that the domain terms are used correctly | Pass | S01 confirmed on 2026-10-08 that the new terms *faint colour* and *contrast ratio* are used correctly (Action Item 1). S01 is also the author; the self-review was accepted on 2026-10-07 |
+| 10 | Abbreviations are spelled out on first use, in the stated language | Pass | WCAG is spelled out at its first use ("Web Content Accessibility Guidelines (WCAG) 2.x"); O6 and SC8 are defined by their tables |
+
+## Overall Verdict
+
+Go — every criterion in the delta passes. S01 confirmed on 2026-10-08 that the new terms *faint colour* and *contrast ratio* are used correctly, so [QC-LANG-001] criterion 9 is closed and the action item is closed. The revision of [BC-001] can be `Accepted`, after which the new phase can be planned against O6 and SC8.
+
+## Action Items
+
+| # | Action | Owner | Due |
+| --- | --- | --- | --- |
+| 1 | Confirm that the new terms *faint colour* and *contrast ratio* are used correctly (QC-LANG-001 criterion 9). **Closed 2026-10-08:** S01 confirmed both terms | S01 | 2026-10-09 |
+
+---
+
+[BC-001]: ../../business-case.md
+[RC-001]: ./rc-001-business-case.md
+[SA-001]: ../../stakeholder-analysis.md
+[QC-BC-001]: ../../../framework/qc/qc-business-case.md
+[QC-LANG-001]: ../../../framework/qc/qc-language-domain.md