The 79th (Cameron of Erracht) Tartan was unique among Scottish Regiments owing to the fact that it was not derived from the 42nd Government (Black Watch) Tartan. It was created by taking the Macdonald sett, omitting three red lines, and imposing the yellow line of clan Cameron. Tartan flashes used as badge backings and sleeve flashes were typically taken from the intersection of the yellow lines.

"The 79th tartan was a source of jealously guarded pride to the Cameron Highlanders. In 1881, when the linking of battalions was taking place, the War Office considered linking the 42nd Royal Highlanders with the 79th Queen's Own Cameron Highlanders. The problem was that both regiments would have to wear the same tartan and obviously the 42nd had precedence. The Camerons were asked by telegram, 'Will your regiment adopt tartan of the 42nd Regiment?' Risking disbandment or amalgamation, the curt reply in the negative left the War Office in no doubt that no one interferes with the 79th tartan."
From THE SCOTTISH REGIMENTS, 2nd edition, by Dr. Diana Henderson. HarperCollins Publishers, 1996.
Even Cameron Prisoners-of-War wished to show their unit pride. In "Prisoners of War News", issued by Headquarters, Scottish Branch, British Red Cross Society, Vol. V, No.4 from April 1943, it was written by Mrs. A.D. Macpherson of Inverness that "we are not now able to send out uniform. By now you should have all got battle-dress, and I am afraid you will have to be content with that. I am trying to send Balmorals and tartan patches."