As a child, whenever I did a painting of the sea, it was invariably Navy blue, just as tree trunks were brown, grass was green and the sky, well, obviously it had to be sky blue. Perhaps, in a headstrong moment, I might add a few wavy white lines to the sea, but that was pushing on the limits of what was known and safe. As an adult, almost daily for the last forty years, I have looked out of my study window across the Clyde Estuary and I have never ceased to marvel at the infinite variety of the colours of the sea. Here, in this tidal zone, where the river begins to broaden out to the sea, flanked by hills and in the path of Atlantic weather systems that bring a goodly amount of cloud and rain, greys tend to dominate. I didn’t realise until I moved into this house on the water’s edge how many kinds of grey there could be. We are all familiar with the title of that book (if not with its contents) Fifty Shades of Grey. From my study I see more shades than that – greys that range from silver to near black; greys which share boundaries with blues, hint at yellows, slide imperceptibly into purples and pinks, fade towards pale phantoms of grey, or by degrees graduate into greens.

I call upon slate to aid me in describing the seascape beyond my window: the grey-blue-greens of Welsh slate; flecked and veined Italian slate; Brazilian black; green-tinged Lakeland slate; from the quarries of Ballahulish, the hues of coal and charcoal and from those of the island of Belnahua slates which plumb the depths of blueness.

Now I must summon metallurgy to help me pin down those elusive greys, invoking precious metals such as silver and platinum; base metals like lead, tin and iron; the rare metalloid, antimony, with its lustrous sheen; and a host of alloys – pewter, gun-metal, chromium, aluminium, steel, spiegeleisen or mirror-iron; and many amalgams of mercury.

Then again, this stretch of estuary brings to mind the ink-wash paintings of the Chinese masters who used only varying densities of black, achieving in one brush stroke tones that ranged from deep black to silver grey. It is reminiscent, too, of certain canvases of Vermeer, Titian or Caravaggio, when employing their monochrome grisaille technique.

Mallards land in our garden every morning, seeking food and, at the end of winter, looking for places to nest. Natural inhabitants of these shores, they encompass in their feathers all the colours of the estuary on which they swim. I speak of the drakes. The ducks, the females, are a speckled brown to blend with the undergrowth amongst which they nest and lay their eggs. In the drakes’ tail feathers are the blacks of the sea beneath thunder clouds, and the whites of foaming crests. Their reddish-brown chests are the colour one sees at low tide when waves crash on the beach, churning up the mud not far below. The area around the underside and middle of their bodies has that same pallor as appears on the water an hour before a misty dawn, a whispered message, a slight lifting of the darkness, rather than light itself. Then there’s that small triangle on the upper back, between the wings, which is mottled and dappled like wind-ruffled patches where a breeze finds passage through a gap in the hills. Above this dappled down is the drake’s iridescent neck: the emerald green of sun-stroked seaweed floating on the surface; the midnight blue of waves shimmering in the starlight; and the orange-yellow beak – the path laid across the water by a melon moon.

Today, in January, with the morning sun still low in the sky, and a layer of bruised cloud hiding the hill-tops, the scene is like an antique black and white photograph that has been tinted sepia, fading and blotching as the silver sulphide salts unevenly deteriorate. There are darker areas where the overhead clouds are thicker and browner. Where the sun’s rays break through are streaks of brass; bands of gold, aureate, clinquant and coruscating; and creamy frills where the washes of passing ships reach the shore. If the Chinese masters had used sepia ink-washes, this morning’s scene might have flowed from their brushes. The greyish tones, though, are never far away, lurking in the corners of my eye.

I think the closest I can come to describing this generosity of greys is to write about my family’s blue-grey eyes. Blue-grey, but flecked with many tints and pinpoints of scattered light; polychromic eyes which alter in hue and tone, in depth and intensity, in brightness and sparkle according to mood, health, or fleeting thoughts; eyes which can be clear or clouded, cold or softly warm; eyes which reflect the world and are windows onto the soul.

I have heard people use the phrase, ‘a melancholy of greys.’ Like grey itself, the word ‘melancholy’ has shades of meaning, including sombre, gloomy, sullen – all of which have, on occasions, applied to the square mile of sea I gaze upon from my house. It’s not the sea, of course, which has these moods - it creates them in the human mind. Such melancholy is not typical of the emotions the grey tones of the Clyde evoke in me. If I could choose a collective noun for greys, rather than ‘melancholy,’ it would be ‘an astonishment of greys’, for their subtle, ceaseless shade-shiftings are a source of endless fascination, surprise, wonder and joy. I have thrilled to the wine-coloured Mediterranean at sunset. I have marvelled at bays lapping with liquid jade in Hawaii and the South China Sea. In the Outer Hebrides I have known the magic of white sand shallows holding turquoise lagoons. Arctic waters of pure, pellucid sapphire are precious memories, as is the ocean afire under a midnight sun. But I am content, more than content, with the greys of the Clyde Estuary. I have not tired of them, nor shall I.

Robin Lloyd-Jones