The word teal comes from the bird of the same name, a small breed of duck known for the iridescent blue stripes on either side of its head. However, it wasn’t until the late 1920s that the term was first used to describe a colour, when it appeared in an advertisement for clothing. Historically, teal’s closest relative is probably verdigris, a bluish-green carbonate that forms on the surface of copper and bronze as they oxidise (the Statue of Liberty is a notable example). Verdigris was the preferred green pigment of artists throughout the Renaissance, although its tendency to fade to brown when applied to canvas, like a withering autumn leaf, eventually resulted in the invention of synthetic alternatives.

Teal is also closely allied to Prussian blue, created by accident during an 18th-century chemical experiment, and indigo, a centuries-old natural dye from the woad plant, whose inky tint resembles teal at its darkest. It wasn’t until teal acquired a name of its own, though, that people developed an obsession with it. In 1948, a Los Angeles couple named Gladys and Gustave Plochere developed the Plochere Colour System – around the same time that Pantone was starting life in New York – to promote colours for their interior decorating business. Teal was one of the shades they chose, and as a result it had its first taste of fashion status during the 1950s and 60s. The novelist Truman Capote stained the wooden floors of his Long Island home a rich teal shade, contrasting it with honey-coloured wooden wall panelling, tan leather sofas and white accents for an original take on coastal style.

Today, teal’s time has come again, and it’s a keynote in Neptune’s autumn/winter collection. “We’ve had teal in mind for a long time as a colour we wanted to work with,” says Rebecca Malyon, head of design and product development. “We felt this shade was really versatile – it works beautifully with a darker contrasting colour, such as Charcoal, and with paler tones, too. It’s softer than navy blue and takes you from summer to winter really well.” The shade appears on upholstery and is a new paint shade for walls and woodwork, and is complemented with terracotta and stone hues. “We like to link our new collections to elements from previous years, so we’ve paired Teal with a hint of Fox, a rich brown-orange shade that our customers have loved since we first introduced it in autumn 2015,” explains Rebecca. “A stone-coloured plaid and a teal floral print on natural linen add further character. We’ve also included a teal velvet, because velvet sums up the winter season like no other fabric can, although wool comes in a close second so we’ve developed two teal-based wools too. It’s a rich palette that can be made more pretty with lighter colours, or played up to be more dark and intense.”

There are other, more scientific reasons why we should embrace teal for our homes. Blue and green light wavelengths are very short, which means our eyes have to make the minimum of adjustments to process them; this is partly why these shades feel restful and balanced. In addition, blue light is used in therapy for SAD (Seasonal Affective Disorder) because the colour helps to regulate the body’s circadian rhythm, or natural cycle of sleep and wakefulness. Such truths do much to dispel the perception of blue as a cold colour, but what about the widely-held belief that dark hues make rooms dark and dingy? Well, it doesn’t have to be that way. The principle of sympathetic colours is important: if you have dark walls, don’t paint the ceiling bright white as it will appear lower; a softer white works better (in years gone by, before the days of tonal palettes, decorators would mix a small proportion of the chosen wall colour into white ceiling paint to achieve this effect).

Finishes matter too. Matte teal walls will absorb light, but velvet upholstery or eggshell paint in the same colour will gently reflect it. By night, teal will appear warmer under yellow-toned halogen bulbs or in candlelight, but chillier under blue-toned LED lights. Adding warm grey or terracotta shades on floors or with accessories helps teal to look its inviting best (as does wood; take a tip from Truman Capote). And there’s no reason to shy away from using dark shades in small spaces: sometimes the best thing you can possibly do is accentuate this defining feature rather than trying to hide it. Awkward wall and ceiling angles can be beautifully camouflaged by using the same dark colour all over. A tiny guest bathroom painted teal, perhaps with brass lighting to give it a golden glow, can be memorable for all the right reasons. In a kitchen, walls and cabinetry both painted in teal make everything feel connected. It feels daring to do, but in reality, it all feels rather dulcet. Plus, teal in the kitchen is a welcome alternative to the dark palettes we’ve seen of late.

Bathrooms and bedrooms are natural settings for relaxing, restorative teal shades. They’re conducive to winding down, to evening bathing rituals and to drifting off to sleep. But there are other possibilities too. Dark blues make a strong statement in a hallway, and used here can have the added advantage of making the rooms leading off the entrance feel bigger and more spacious in comparison. Comforting, cocooning and boasting endless potential, there’s really no end to teal’s charm.