When painter Sheila Girling, who died on Saturday aged 90, met sculptor Sir Anthony Caro in 1949 they began a discussion about art which continued over 63 years of marriage until his death in 2013.

She was a colourist who used her talent in vibrant semi-abstract collages of cut-up acrylic canvas and in his sculptures.

Lady Caro was born in 1924 in Birmingham into an artistic family – one grandfather was an artist, the other an art dealer.

Her mother opposed her ambition to become a doctor, for fear of germs, insisting she went to art school but never marry an artist.

After attending Birmingham Art School, she joined the Royal Academy Painting School in 1948 and won medals for portraiture and painting.

She met fellow student Sir Anthony in a drawing class and they married six months later but she retained her maiden name professionally.

She continued to study and paint until their first son Tim, now a zoologist, was born in 1951.

She felt nurturing a new life was more important than anything she could create in the studio.

In 1953, the Caros settled in Hampstead, buying a stable block and old smithy in Frognal.

It was there that Sir Anthony made his iconic steel sculpture Early One Morning in 1962, which Lady Caro famously advocated painting red instead of green.

She was still advising him on colour in 2013, choosing the exquisite blue of the Perspex disc in Blue Moon.

When Tim and his brother Paul, born in 1958 and now an artist, went to school, she returned to painting full-time.

She talked with admirable candour about the difficulties involved, not least being married to a successful artist, and about finding herself in experiments with collage.

In the early 1970s, she began working in acrylics, a medium encountered in America where the family lived for a time when Sir Anthony was invited to teach at Bennington College in 1963.

Between 1982 and 1992 the Caros ran the innovative triangle workshops in New York State. She believed the pressure involved led to a more dynamic style in her collages, made on a horizontal plane.

Travel was always a stimulus and she responded, in watercolour too, to locations ranging from Dorset, where the family has a cottage, to India, whose hot colours made her palette richer. Since 1992 Sheila had a studio in the former Dunhill pipe factory in Camden Town.

Her first solo exhibition toured in Canada in 1978 and she had regular shows in New York and at the Francis Graham-Dixon Gallery in Clerkenwell. Group shows included the Camden Art Gallery in 1981 and numerous Royal Academy Summer Exhibitions.

A retrospective opens at Annely Juda Fine Art in central London in September.

Sheila Caro was an ambitious, accomplished artist who had a welcoming manner and was delightfully courteous.

So it surprised no-one who knew her when her husband claimed he only accepted a knighthood in 1987 ”so that Sheila could deservedly be called a lady”.

She is survived by her sons and grandchildren: Barnabas, Benjamin and Emma.