Plenty of Highlanders getting up to mischief in Africa. But I'm not sure what you mean by "Darkest" Africa. The gaming genre of that name is kind of nebulous, but even if you stretch it to its extremes it doesn't really ever cover anything where Highlanders in kilts got involved; or indeed unless you extend it to cover the Great War in East Africa, no British regulars whatever.
Best I got for you, I'm afraid...
He's either KAR or Rhodesian Native Regiment, I forget which. Dates from the Great War era (only the drummers and buglers were forced into this fancy dress get-up). Some KAR units are said to have worn kilts made from khaki cloth during the war, due to a shortage of shorts.