The first nine albums were originally published in black and white, with colored editions to appear later:
- Tintin in the Land of the Soviets (never redrawn in colour )
- Tintin in the Congo
- Tintin in America
- Cigars of the Pharaoh
- The Blue Lotus
- The Broken Ear
- The Black Island
- King Ottokar's Sceptre
- The Crab with the Golden Claws
Which books have been entirely redrawn? I can confirm that Tintin in the Congo, Tintin in America, Cigars of the Pharaoh and The Blue Lotus were, but I have no first-hand experience with the latter titles.
I assume that the books published only in color haven't been significantly modified.
The opening frames from the 1931 and 1946 versions of Tintin in the Congo (source)