Prior to District High School days, Onewhero School colours were green and white. When the school became a District High School in 1955, blue and grey were chosen as the colours for the uniform. Today, the school colours worn are royal blue and navy with a touch of gold.

Mr Alan Shepherd, the headmaster at the time, chose the motto EACH FOR ALL - Te Kotahi Mo Te Katoa. We share the motto with Alexandre Dumas' characters, 'The Three Musketeers': Each for all and all for each. Or to go back even one step further, it was an ancient Latin saying: Singula sint omnium et omnia singulorum.

Mrs Kath Bouskill thought of the idea of the crest with three crowns representing the three contributing districts (Onewhero, Te Kohanga, Opuatia) placed upon a symbolised river (Waikato).