I see the OP said an RSA hunt, so will try to add some general (note general! There are of course exceptions in all of the regions) info that may be helpful in selecting hunting clothes...
Firstly, there are very few places in RSA that get truly cold. Sure up in the mountains if a cold front hits in winter then all bets are off...
As a general guide - June through August are the cold months. By cold I mean early mornings may be around the freezing mark and the midday peaks around 18-25 deg C. This does of course vary by province. October through March are hot. Winter is the dry season, so rain is highly unlikely (other than the Cape Town/Western Cape region - but not that much hunting happens there)
If you're hunting in the bushveld, which usually means the coastal belt, plus Zululand/Northern Natal and Limpopo, then it never gets cold really. You're more likely to have heat issues from over-dressing rather than being too cold.
Olive and camo patterns will be good and try to select fabric that is not synthetic. If you rub your nails over the fabric and it makes 'whistling' noise then it's going to be noisy going through thorns and branches. Not good. Tougher fabrics that do not collect burrs or hook on thorns are recommended. Unlined 'bush' jackets work well - you are dressing for protection from the flora, not so much for warmth.
Hunting in the mountains (Drakensberg in E Cape, Natal and Southern Free State) - you probably need to be on your toes with regards to colder weather. These areas can be exposed and if the wind blows it is chilly. Given that you will be clambering up steep terrain, you are likely to be exercising hard and sweating. So layers are good and light-weight clothes are a plus.
Colour-wise, these areas are generally bleached 'white' in winter so khaki colours can work.
The plains/savannah regions are generally the interior (N Cape,Kalahari, Natal Midlands, Free State, Mpumalanga, North West ) are probably the least demanding from a clothing perspective. Avoid overly pale/light-coloured clothing - anything from dark-khaki through to olive should be fine.
In general, my advice would be to try and wear layers. Conditions do tend to fluctuate quite a bit from pre-dawn when it's chilly and you are usually sedentary in a vehicle (i.e. not generating much body heat) to midday when it may be hot and you're racking up the miles. A warm jacket worn in the morning and evening can be left in the hunting vehicle once you're hunting. A light unlined bush jacket once you're hunting should be more than adequate for warmth other than in 'extreme' cold (by RSA standards). Camo is legal in RSA so if that's your preference, no issues using it - please note that camo is (technically) banned in Zim though.
My 2c on shorts - leave them to the PHs
The places where it's hot enough to motivate shorts are generally thorny - having legs scratched to hell is not fun. And if it's that warm, chances are you will end up with sun-burned legs too. Torn-up, burned legs inside long trousers the next day is also not so comfortable but helps cement the lesson!
Gaiters and a buff are always a good idea. Gloves are not essential but may protect against thorns if you're in the thick stuff, or be needed if it is very cold. A broad-brimmed hat is important - just make sure that it doesn't have shiny metals studs or badges on. In thick bush, a hat may catch a lot of thorns and branches, in which case switch for a cap.
Try to ensure that your new hunting clothes have had a few washes before hunting - new clothes often have a bit of a sheen to them. And as has been mentioned, try to wash them in non-smelling detergent if possible.
The importance of well worn-in footwear has been raised many times. I would caution against light-weight trainer/running shoes unless you really know the areas you're going to. Medium weight leather ankle boots are a much safer bet - make sure yours are comfortable!
Your go-faster running shoes will be susceptible to thorns and grass seeds may also penetrate them.
I would advise comfortable footwear for the evenings after your long day of hunting, something to let your tired, sweat-softened feet dry out and recover - sheepskin slippers next to the fire are a real pleasure!
Hope that helps!
