How does Porcelain blue (No.20 C 33) by BS 4800 compare with Johnstone's’s closest paints? The nearest match by perceptual distance is Johnstone's Cold Iron (ΔE 0.8, “identical”). 3 more Johnstone's colours sit within ΔE 4 — close enough that the difference is hard to spot once paint’s on the wall. These 4 Johnstone's paints are all priced at £12.36 per litre.
BS 4800 Porcelain blue vs Johnstone's
4 closest Johnstone's matches ranked by ΔE
ΔE (CIEDE2000) is a perceptual distance metric — lower means a closer match. Matches under ΔE 2 are typically indistinguishable; ΔE 2–4 looks “the same” once dry on a wall; ΔE 4–6 is noticeable side-by-side. Always view a sample pot before committing — screen colours and lighting vary.
| Colour | Number | ΔE | Match quality | Price/L | Price/m2 |
|---|---|---|---|---|---|
| Cold Iron | — | 0.8 | identical | £12.36 | £2.06 |
| Stratosphere | — | 1.1 | near-identical | £12.36 | £2.06 |
| Memory Lane | — | 1.6 | near-identical | £12.36 | £2.06 |
| Sleep Baby Sleep | — | 1.9 | near-identical | £12.36 | £2.06 |