Margaret Mellis, Sainsbury Centre for Visual Arts, Norwich

It would be folly to underestimate the energy and achievements of older people. Think of Titian, John Cowper Powys, the late creative rage of W B Yeats. The Scottish-born painter, sculptor and collagist Margaret Mellis, now in her 95th year, was approximately 70 years old when she began to make the wooden constructions for which she is now most justly celebrated, and it is these pieces that dominate the career-long retrospective of her work in Norwich.

Until then, her work had passed through several fruitful phases of self-interrogation. Before the Second World War she studied at the Euston Road School in London. During the war she lived and worked in Cornwall and there she came under the influence of Naum Gabo, Barbara Hepworth and Ben Nicholson, all in love with various forms of abstraction. The shadow of Russian Constructivism hung over her. Severity of form was everything.

But no, not everything to Mellis. Mellis was in love with colour, too, and during the middle phase in her career, she made wooden assemblages, often severely geometric, which admitted colour, though grudgingly because the teachers in her head were warning her off.

After the death of her second husband in 1984, she was living in a house overlooking the sea. Her materials, she began to notice, were all around her. Bits of driftwood, often blistered, broken. All sorts of shapes, sizes and colours: a bottle shape, in blue, with an angelic form; a splintered length of red wood, which looked like a bloodied spear.

She amassed all this stuff and, over the years, various forms began to take shape. There is much colour here, but it is colour that was left after the sea had done the worst of its scouring. The crudeness of the bits from which the works are fashioned helps to give them a wild energy. They are wayward, wonky, full of sly humour. It is as if Mellis is holding up those severe influences from her past – Gabo, Hepworth, Nicholson – and having fun at their expense.

They didn't have colour running in their veins, did they? They didn't quite see how a colourless world was a slightly emasculated one, did they?

To 31 August (01603 593 199)