Short answer
This is metamerism: two colours made from different pigment combinations can match under one light source and differ under another. Approve against a physical standard under at least daylight (D65), a store light (TL84) and incandescent (A), and match on the real substrate and gloss, not on a different material.
Likely causes
Different pigment mix from the target
Same visual colour from different pigments reflects light differently.
Gloss or texture difference
Changes how colour is perceived even with identical pigments.
Substrate difference
Foam density, skin versus core, or a different base polymer.
Non-standard lighting at approval
Judged by a window or an office lamp.
How to diagnose it
- View under D65, TL84 and A in a light booth.
- Measure spectral curves with a spectrophotometer.
How to fix it
- Re-match with a pigment combination close to the target under multiple illuminants.
- Match on your actual substrate.
How to stop it coming back
- State the end-use lighting in the brief.
- Supply a physical standard, not only a colour code.
Where this problem appears most
Send us your batch number, PU system and a photo of the defect and our technical team will help you trace the cause. Ask a technical question.
