Entrants in the Rainbow Run, organised by Sport Waitaki, will wear white, and walk, jog or run around a 5km course with five colour stations sponsored by Oamaru businesses. At each station, the businesses' staff will try to cover participants with coloured corn starch powder.
Sport Waitaki co-ordinator Kate Cartwright said the event was not competitive but a fun day to promote healthy exercise.
It was popular overseas, but had only been held once before in New Zealand, in Christchurch.
Already, just over 300 entries had been received and replies were still to come in from schools.
''We are thrilled with the response. It's a lot better than we expected with a first-time event. I think we will reach our limit of 600 before the day,'' she said.
The number had to be limited because the coloured powder was imported from India, where a similar event, the Holi festival in March, attracted thousands to celebrate the beginning of the spring.
The response was so good that Miss Cartwright hoped to make it an annual event.
Most entries had come from North Otago, but there had been others from as far as Gore and Christchurch. All ages had shown an interest.
While the event was all about fun and positive energy, the occasion promoted healthy living, catering to all abilities, from first-time runners to elite athletes.
The event would start at 11am, in front of the grandstand, and people travelling to the All Blacks' test in Dunedin that night could stop off for some fun.
The racecourse would open at 10.30am, with music, entertainment and a ''group warm-up''.
