RAL 7031 Blue Grey

RAL 7031 Blue Grey: a cool grey with a clear blue bias

Blue Grey is a mid-to-dark grey with an unmistakable blue bias. It is widely used on machinery, industrial equipment and facades, and cool blue-greys of this family are also familiar from maritime and utility applications. In scale it suits ships and marine fittings, machinery, trucks and vans, and building details. It is also a helpful tone for modern equipment and interiors, and a good base for salt and grime weathering on nautical subjects.

Getting the tone right

Neutral greys and subtle tones are unforgiving: a slightly uneven coat reads as a different shade under the clear. This colour is formulated for smooth, even coverage in thin coats, so every panel matches.

How to apply

1. Shake the bottle for at least 60 seconds.
2. Prime with a grey primer and let it dry fully.
3. Airbrush straight from the bottle, no thinning needed. Use a 0.2–0.4 mm nozzle at around 20 PSI (1.4 bar) and apply light, cross-hatched coats, letting each one flash off before the next.
4. Let the paint cure overnight before masking or clear-coating.
5. Seal with a water-based clear coat: gloss for a factory shine, or satin or matte for work vehicles and interiors.
6. Clean the airbrush with water before the paint dries.

Why modelers choose Koloi Aqua

• Ready to spray: no guessing thinning ratios, the same result from every bottle
• Cleans up with water, so there are no strong solvent fumes at the bench
• Fine pigment grind for 1:8 to 1:72 scales, so panel lines and detail stay crisp
• One system: primer, colour and clear designed to work together

Shelf life

Estimated shelf life of more than 12 months when stored tightly closed between +10 °C and +28 °C, away from frost and direct sunlight. Shake well before use; if the paint has thickened or separated and does not remix, do not use it.

💡 Need a colour we don’t list? Our colour lab matches RAL, RLM and OEM paint codes on request.

The on-screen image is indicative: the final tone depends on the primer, the number of coats and the clear coat. Keep out of reach of children. Safety Data Sheet available on request.