Keep it simple, plain and practical for your comfort while on Safari. If you are hiking, gorilla or chimp tracking, pack trekking strong shoes or jungle boots for hiking, long sleeved shirts offer proper protection for you from thorns and insects, long stockings (if putting on shorts), comfortable jeans (pants/trousers).
Others may include a hat or cap which comes in handy, Khaki is good for its color and feels good as you wear it, some comfortable shorts. dresses and blouses (female). A rain jacket also comes in quite handy.
IMPORTANT: When packing for a Safari, keep it to just the essentials and keep it light. Just ensure you have packed what is just enough but considering all weather conditions.