It could have been the 1st Boer War ...
The First Boer War also known as the First Anglo-Boer War or the Transvaal War, was fought from December 16, 1880 until March 23, 1881. It was the first clash between the British and the Transvaal Boers
The war began on December 16, 1880 with shots fired by Transvaal Boers at Potchefstroom after Transvaal formally declared independence from Great Britain. It led to the action at Bronkhorstspruit on December 20 1880, where the Boers ambushed and destroyed a British army convoy. From December 22 1880 to January 6 1881, British army garrisons all over the Transvaal became besieged.
The Boers were dressed in their everyday farming clothes, which were a neutral or earthtone khaki clothing, whereas the British uniforms were still bright scarlet red, a stark contrast to the African landscape, which enabled the Boers, being expert marksmen, to easily snipe at British troops from a distance. Other significant advantages to the Boers included their widespread adoption of the breech loading rifle, which could be aimed, fired, and reloaded from a prone position, and the Boers' unconventional military tactics, which relied more on stealth and speed than discipline and formation.
The besieging of the British garrisons led to the Battle of Laing's Nek on January 28 1881 where a British force composed of the Natal Field Force under Major-General Sir George Pomeroy Colley attempted to break through the Boer positions on the Drakensberg range to relieve their garrisons. But the Boers, under the command of P.J. Joubert repulsed the British cavalry and infantry attacks.
Further actions included the Battle of Schiunshoogte (also known as Ingogo) on February 8 1881, where another British force barely escaped destruction. But the final humiliation for the British was at the Battle of Majuba Hill on February 27 1881, where several Boer groups stormed the hill and drove off the British, and Colley was killed.
Yours aye
Paul