Think about it this way. Look at the colonisation system in Victoria Revolution to give you an idea of what way we are going. Provinces can be colonised by any country. However you have restrictions on who can colonise it. Naval bases determin range, technology determines which provinces you can colonise. Thus countries like Britain get an instrinsic advantage, Serbia on the toher hand has to work a bit to join the colonial game (a coastline is a good start here). However I see no reason why if you do ahistorically well as Serbia you should not be allowed to carve out your piece of Africa.