RAF Dark Slate Grey BS 634

RAF Dark Slate Grey BS 634: the green-grey of the Temperate Sea Scheme

RAF Dark Slate Grey BS 634 reproduces the British Standard Dark Slate Grey, a dark grey with a clear green cast. In the Temperate Sea Scheme it was paired with Extra Dark Sea Grey on the upper surfaces of RAF and Fleet Air Arm maritime aircraft, where it gave the camouflage its characteristic green-grey contrast. This water-based acrylic is formulated for the airbrush and gives a smooth matt film, easy to mask for hard-edged disruptive patterns. Suits Coastal Command and FAA kits such as Swordfish, Beaufighters, Hudsons and Sunderlands.

The problem with matte finishes

A matte finish hides nothing: fingerprints, uneven coats and gloss patches all show. Spray light, even coats, avoid handling the parts, and finish with a matte or satin clear to keep the sheen consistent.

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, decals or weathering.
5. Seal with a water-based clear: matte or satin to keep the military finish, gloss under decals.
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, FS and BS paint codes on request.

The on-screen image is indicative: historical military colours varied between factories, batches and weathering, and 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.