Was Sudan renamed

Yes, Sudan was officially renamed as the Republic of Sudan in 2011 after the secession of South Sudan.

Which colonizer gave independence to Sudan and who was the prime Minister/president of the colonizer at that time

Sudan gained independence from British and Egyptian colonial rule on January 1, 1956. The Prime Minister of the United Kingdom at the time was Sir Anthony Eden, who played a role in the granting of independence to Sudan.

I thought it was colonized by the French

Sudan was actually colonized by the British and Egyptians, rather than the French. The Anglo-Egyptian Condominium, established in 1899, governed Sudan until its independence in 1956. The French did have colonial presence in nearby countries in Africa, but Sudan was not one of their colonies.