Keep one maker-colour identity. In Visual metadata choose Annual chronology. Use Quick year entry to select inclusive start/end years, optional additional periods and exclusions, then Save manual years. No evidence, citation or reason is required. Manual selections are explicitly unevidenced availability, not independently confirmed; they never replace the separate annual assessments. To record evidence later, choose catalogue availability, production, surviving object, document, scholarship or interpretation and add its citation and statement. Adding contradictory evidence never removes earlier sources.
Assess individual years or ranges as CONFIRMED, PROBABLE, UNLIKELY or UNKNOWN. Each assessed year requires selected evidence covering that year, except UNKNOWN. Explicit interpretation evidence can explain an inference. Bulk changes preserve already assessed years unless replacement is explicitly selected. Every replacement appends before/after history; stale forms are rejected.
Unknown years remain UNKNOWN and UNLIKELY never means impossible. Legacy first/last dates show extent only. The timeline shows annual assessments, with evidence links and separate viewing/export permissions. A collection object dated to an UNLIKELY year gets an advisory only: no object, attribution, date or catalogue relationship is automatically changed. The Makers’ Colours database is the preferred curated chronology for Whitefriars and Whitefriars-manufactured Wuidart Wealdstone colours, particularly 1931–1980. Earlier reconstructed dates retain their uncertainty. The withdrawn historical timeline PDF is not used to populate years. No dates or HEX values are invented.