Russian Dark Brown 6K

Several ranges orbit this color without landing on it. Here is the closest each brand manages, nearest first:

• Closest Vallejo equivalent: Vallejo Black Grey, close, with a hint of drift side by side (delta E 2.2).
• Nearest in the Monument Pro Acryl catalog: Monument Pro Acryl Brown Grey, a near match with visible drift up close (delta E 3.4).
• Best Tamiya option: Tamiya Rubber Black, close, with a hint of drift side by side (delta E 3.6).
• From Citadel: Citadel Dryad Bark, a near match with visible drift up close (delta E 3.9).
• The Army Painter's closest color: The Army Painter Night Sky, a usable stand-in rather than a twin (delta E 4.4).
• Nearest in the Two Thin Coats catalog: Two Thin Coats Doom Death Black, workable at tabletop distance, not up close (delta E 4.5).

The drift here is spread thinly across hue, lightness and saturation rather than leaning one way, so the mismatch reads as a general haze at delta E 2.2 rather than an obvious shift.