Choosing Paint Colours for Harbour Light

Colour behaves differently by the sea. A grey that looked calm and sophisticated on a small card in a shop can turn cold and blue against Wellington’s harbour, or wash out to almost nothing on a bright summer afternoon. Light bounces off the water, cloud shifts the tone from minute to minute, and the sun’s UV works steadily on every pigment. Choosing exterior colours for a waterfront building is partly about taste and partly about physics.

Why harbour light is different

Three things change how colour reads near the water.

Reflected light. Water acts like a giant, moving reflector. Walls facing the harbour receive light from the sky and from the surface of the sea, which tends to brighten and cool colours. A mid-tone can read a shade or two lighter than expected.

Strong UV. New Zealand has high ultraviolet levels. Research by NIWA scientists has found summer peak UV here to be roughly 40 percent higher than at similar latitudes in the Northern Hemisphere. UV breaks down the binders and some pigments in paint, which shows up as fading and chalking. Some colours, particularly certain bright reds, yellows and deep blues, are more prone to fade than earth tones and neutrals.

Changeable skies. Wellington’s weather can flip from hard sunshine to flat grey cloud in the space of an hour. A colour needs to look right in both. Warm whites and soft neutrals usually handle the switch better than stark whites, which can glare in sunshine and turn dull under cloud.

Dark colours and heat

Dark exteriors are popular, and they can look striking against the sea and the hills. They also absorb much more of the sun’s energy than light colours, so the surface of the cladding gets hotter. That heat can matter more than the look.

Paint makers describe how much visible light a colour reflects with a figure called light reflectance value, or LRV. The lower the LRV, the darker the colour and the more heat it tends to absorb. Many cladding suppliers set a minimum LRV for their products, often around 40 to 45 percent for painted timber weatherboards, because darker colours can cause timber to move, crack, bleed resin or cup. Going darker than the supplier allows may not break the Building Code, but it can void the product warranty.

If you want a dark exterior, ask:

• What is the cladding? Some products are designed for dark colours. Others are not.
• What does the supplier allow? Check the warranty documents for an LRV limit.
• Is there a heat-reflective option? Some paint ranges include dark colours formulated to reflect more infrared energy, which can keep surfaces cooler than an ordinary paint of the same shade.

Dark colours also show salt deposits and chalking more readily, so they may need washing more often on the waterfront.

Choosing a sheen

Sheen affects both appearance and performance.

• Flat or matt finishes hide surface imperfections well and look soft in bright light, but they can hold dirt and salt more readily.
• Low sheen is the common choice for weatherboards and walls. It balances a subtle look with reasonable cleanability.
• Semi-gloss and gloss finishes are often used on joinery, trims, doors and handrails. They are harder wearing and easier to wipe clean, but they show every dent and brush mark, and in direct harbour sun they can glare.

A common approach is low sheen on the main walls and a higher sheen on trims, which both protects the parts that get handled and adds a little definition.

Testing swatches properly

The single most useful thing you can do is test colours in place.

1. Go big. Paint a sample at least A4 size, and preferably larger, on a board or directly on the wall.
2. Test on more than one side. The harbour-facing wall and the sheltered side of a building can make the same colour look quite different.
3. Look at different times. Check the samples in morning light, at midday, late afternoon and on a cloudy day.
4. Look from a distance. Colours tend to read lighter and brighter across a street than they do at arm’s length.
5. Check against fixed elements. Roof colour, joinery, stone, paving and neighbouring buildings all affect how a new colour sits.

In a unit title building, exterior colour changes usually need body corporate approval, and some buildings have a colour scheme set by the original design. Older buildings or those in heritage areas can also have planning constraints. Check before you buy paint.

Getting advice

Swatches and online tools only go so far. For a whole exterior, getting colour advice from an experienced painter is worth it. A painter who works on coastal buildings will know which colours have held up in salt air, how particular products behave on different claddings, and how to balance a colour you love with the limits of the substrate and the warranty. They can also point out preparation issues, such as chalky surfaces or failing previous coatings, that affect how any new colour will look and last.

Living with the choice

A well-chosen exterior colour should still look right in ten years, after countless southerlies, salt spray and summer sun. Leaning towards UV-stable pigments, respecting the cladding’s limits, picking sheens that suit each surface and testing in real light all help get there. For more on durable coatings near the sea, see salt air and painted exteriors, and for wider guidance on choosing materials, the Level material use pages.