The recommended palette
None of these are required, but if your module needs to drop into a row of unrelated modules at a meet, this is the colour vocabulary it should speak. The skyboard tones are deliberately soft and slightly desaturated — strong cobalt blues will read as wrong against any neighbouring module. The fascia greens lean muted and eucalyptus rather than bright lawn green. The ground tones are earthy because that is what almost any Australian setting looks like at ground level once you stop staring at brochures.
Skyboard
The skyboard is the rear panel that hides the messy view of the wall, lights, and other people's elbows behind your scene. It also gives the eye somewhere to terminate, so the trains are not running against a backdrop of shoes and exhibition carpet.
For N scale, 200 mm of skyboard should be visible above the module's deck — total board height around 250 mm once you allow for what sits below the deck surface. For HO/OO scale, visible height steps up to 350 mm with a total of around 410 mm.
The top corners should be softened with a small radius — somewhere up to about 18 mm, roughly the diameter of a 20¢ coin. A sharp 90° corner reads badly when modules are joined in a row and one neighbour's skyboard is taller than yours.
Mounting needs to be removable for transport. Common methods, all acceptable: Velcro patches, wing-nut bolts through the rear apron, bulldog clips along the top edge, or a slide-in 3 mm plastic moulding clip. Whichever you choose, the skyboard should come off without tools-and-swearing — you'll do it every meet.
The recommended sky colour is a soft pale blue. The four chips above are the ones most often seen and most likely to sit politely beside a stranger's module.
| Skyboard colour | Pale blue | desaturated |
|---|---|---|
| Fascia colour | Black or eucalyptus green | unified along row |
| Ground base | Earthy brown or grey | never bare wood |
| Inter-track ballast | 8 mm gap | between front/back tracks |
| First-pass scatter | WS Burnt Grass T44/T1344 | common starting point |
| Peco track underlay | Optional | for non-Unitrack sections |
| Edge clear zone | Last few mm | no loose materials |
Front fascia and sides
The fascia and sides are modeller's choice within a conventional palette. Most exhibitors choose either a flat matte black or one of the eucalyptus greens — Colorbond Wilderness/Rivergum, British Paints 269, or Dulux P22.E7. The point isn't that one looks objectively better; the point is that a row of strangers' modules at an exhibition reads as a single layout rather than twelve separate woodwork projects when the fascia colours align.
If your local group has settled on a colour, follow it. If you're new to the format, matte black is the safest default — it disappears under exhibition lighting and lets the scenery sit forward.
Ground colour
Bare wood is not acceptable as a ground covering. Even a beautifully built module that runs flawlessly looks unfinished if the deck is showing through, and the eye is unforgiving about that under bright lights.
The recommended starting tones are earthy. For a warm look, Berger Safari Dust or British Paints Pure Earth (101) — both warm browns. For a cooler, drier-looking landscape, British Paints Fox Hunt (282) or Dulux Grey Scape (P04.A2) — both earthy greys. Apply this base colour to every part of the deck that isn't track, before any scatter or static grass goes down. It hides the gaps between texture, and matters most where scatter has thinned over time.
What goes on top is at the modeller's discretion: static grass, flock, ground foam, ballast, or any combination. Woodland Scenics Burnt Grass (T44 / T1344) is a common starting scatter for Australian-looking dry country and a good first jar to buy if you've never scattered before.
Ballast
Kato Unitrack ships with ballast already moulded into its base — the grey shoulders are part of the plastic. There's nothing to add along the main running lines.
Ballast is therefore only needed for the 8 mm gap between the front and back tracks (which is bare deck), plus any non-Unitrack you've installed inside your module — sidings on Peco code 55, hand-laid spurs, or whatever else.
The closest commercial matches to Kato's moulded grey are Woodland Scenics Fine Gray (B1375) and Chuck's Soft Grey, though Chuck's has become hard to source. Either gives an acceptable visual continuity between the moulded shoulders and the loose ballast you're applying yourself.
At the joining face
Keep loose materials — scatter, ballast, ground foam, static grass — well away from the last few millimetres at each module end. Trees, signs, signals and any overhanging structure must respect the side and overhead clearance gauges. The module sitting next to yours at the next meet is unknown — it could be a signal box, a tunnel portal, or a flat paddock. Plan as if it will be all three at different shows.
Identify your module
Put your name on every module you build, preferably written or stuck on the back of the skyboard where it can be seen during set-up but not from the front during the show. Meet organisers will additionally tag each module on the night with a descriptive name (what's on it) and origin state or town, so visitors can read along the layout.
Era and prototype
The standards do not prescribe an era, country, or prototype. Modellers run anything from Australian outback diesel branchlines to Japanese Shinkansen on the same continuous loop — and that's the point of the format. What the standards do require is the edge clearance and skyboard height; what runs over the top is up to whoever built the module.