Eradicating illiteracy seems a little ambitious. Many European countries had not achieved universal literacy by the 1960s, let alone their colonies. But sure, if the British or other European power made a focused effort on their colonies they could have greatly reduced illiteracy.
In the short term I don't see any major changes, but by the 1950s this could have a ripple effect - More agitation for decolonization in the colonies proper, and for equal opportunities in places like South Africa, as populations become more aware of their situation and have a greater desire for political involvement.
Many African nations, like Sierra Leone or Uganda, once independent, could see higher rates of economic growth than in OTL, more stable governance and less bloodshed, as well as more orderly independence movements and better post-war relations with the West.
It wouldn't have been a magical solution to Africa's problems, and the continent would still have suffered from the proxy wars of the Cold War, but it would have helped enormously.