Vivian Justus (Coll) McDonald - or Brother Mac as he was known to thousands of students in 56 years of teaching - was an unlikely picture of a Christian Brother.

His Split Enz mop of curls and short back and sides haircut conformed to early '70s school rules (barely), while his black cassock included all colours of the rainbow from his art classes. Once when a mother pointed out that his pullover was on inside out, he replied: "There is so much paint on the outside, it looks more presentable this way." Art was such a large part of his life and a means for him to positively influence the lives of so many others.

He was born on the family property at Williamsdale, outside Canberra, to Vivian and Clare McDonald, the eldest of three boys. Educated at St Patrick's College, Goulburn, he joined the Christian Brothers in 1944, with his first profession in 1946 and final profession in 1952.

Mac's "missions" were in Queensland (Toowoomba, Maryborough, Bundaberg and Mackay) from 1948 to 1960 when he went to Waverley College, then Burwood. In 1969, Mac arrived at St Pius X College, Chatswood, where he stayed until his retirement in 2003.

In an era when good religious communities were built on good order among the brothers, Mac saw other values and insights as priorities. These were based on people, their lives, their hurts, their joys, and for them, in the name of his God and the brotherhood, he poured himself out.

Many men when faced with a seemingly intolerable bind of "keep the religious rule and it will keep you" left the congregation to find other paths in life. Mac lived in and through it, but never stopped asking "Why?" He was unconventional. He was one of the few people whose lives had little to do with a 24-hour cycle. On occasion, he would be coming home as everyone else was heading for morning prayers. He may have worked all night, or, when he missed the last train from Burwood to Chatswood, he simply went to sleep on the platform bench and caught the first train of the morning.

An old army hut became the St Pius art room and Mac's chaotic base for much of his life. From here the syllabus was taught, but that was such a small part of his work. "Bad kids" found sanctuary there, lonely kids were never lonely inside those paint-splattered walls. JimiHendrix posters were screen-printed for fetes and uniforms stained forever with poster paint. Pottery was baked, copper jewellery was belted beyond recognition, enamelled cufflinks and pendants were produced for Christmas presents and a blind eye was turned to cigarettes that would have earned the strap elsewhere.

Serious artists such as the Archibald Prize winner Craig Ruddy were inspired. Even a parent's garage door became the canvas for a Mac mural - a landmark for taxi drivers for decades. Only Mac could employ an assistant art teacher who could neither read nor write and have the older boys tutor the man in Mac's office. All done with a minimum of fuss or bureaucracy and all making perfect sense: why wouldn't you employ an illiterate teacher and give him a hand?

When he wasn't working around the clock at St Pius, Mac was on a train to the Obley Education Centre in St Marys to help kids who couldn't fit into the school system, trying to make life better for those with the odds stacked against them.

Despite suffering the constant strain of a manic depressive condition, he had an extraordinary sense of personal security and at-homeness with the world. He was as comfortable with the poor or the wealthy and could equally affirm the humble, drab efforts of one of his students as he could be thrilled by international masterpieces.

Having a mental illness never seemed to affect his optimism; rather, it probably gave him greater compassion for people. His hope and indomitable spirit always came to the fore. Mac's spells in hospital with depression usually ended up with him making a personal contribution to Australia's mental health system, including art lessons for psychiatrists, nurses and other patients.

An advertising man and St Pius parent, Ross Quinlivan, couldn't believe a man so passionate about art had never been to Europe to see the works of the masters. A trip was organised, Mac was to have a travelling companion - a chaperone - whom he gave the slip at the earliest opportunity and explored Europe's galleries on his own terms. He revelled in the artworks he had known only in books. The trip had an extraordinary and lifelong effect on him, providing inspiration he passed on to his students.

He was a man who simply could not say "No". While "Yes" was always Mac's response, usually months ahead of a deadline, work rarely started until hours before a crisis. Typically, costumes for a school production of Joseph and the Amazing Technicolor Dreamcoat were started, not finished the night before the show and dried with hair dryers the hour before curtain.

Even in retirement, he taught art appreciation and art history at the University of the Third Age, giving some an interest in art, inspiring others in his classes to travel to Europe to see artworks first-hand as he had done years before.

In his latter years, Mac's health deteriorated badly. From walking stick to frame to wheelchair, he desperately wanted to stay at St Pius and maintain his independence, which he did until two years ago. The running joke at that stage was that Mac maintained his independence by 10 other people sacrificing theirs. Eventually he moved to the Charingfield nursing home at Waverley where he was cared for so fondly by Joan Rafferty. The carpets at Charingfield may never recover from Mac's oil paints.

After serious bouts in hospital his last stop was the Gertrude Abbott Nursing Home, where he was persuading nurses to pose for his charcoal sketches right up to the end. Mac died comfortably and peacefully in his sleep.

There are so many people whose lives have become distinctly richer for their contact with Mac. Each one felt they had a special relationship with him, making their contact one of a kind and unrepeatable. He created in his Christian Brothers the capacity to listen to people's pain and not to judge. And he enriched the lives of his students with a compassion and honesty rarely seen. As one of his former pupils said: "You can't help loving that man; he radiates goodness." Another Christian Brother said: "To be able to say that you were a friend of Mac is a gift to be treasured beyond price."

He maintained his sense of humour to the last. Shortly before he died, Mac saw a former student, Father Anthony Riley, arrive. Mac's Spike Milligan-esque observation was: "Gee, I must be crook if you're here."

He probably summed his life up earlier in the year when he painted the following banner beside his bed at the Gertrude Abbott Nursing Home: Life is a big canvas; throw all the paint you can at it.

God bless him.

Brother John Thornber, Brother Graham Rossiter and Kim Terakes.