Bruce Banner's irritable alter ego had gray skin during his initial transformations in The Incredible Hulk #1 (May 1962), and then began turning green with #2. Throughout his early exploits and quarrelsome dealings with the original Avengers, Hulk was befuddled at times but remained reasonably articulate nonetheless.
By the time the Defenders formed in Marvel Feature #1 (December 1971), however, Hulk's vocabulary was simplistic. This held true throughout his lengthy membership with the non-team (outside of the rare occasion when Hulk retained the brains of Bruce Banner).
When Banner later began transforming regularly into the gray-skinned Hulk, his verbal skills returned to the level they had been during Hulk's first appearances. This gray variation of the character was now distinct from stupefied green Hulk.
Yet the gray version of Hulk retained a modicum of loyalty to Sub-Mariner and Dr. Strange just the same. When the three heroes teamed up in The Incredible Hulk #370-371 (June-July 1990), they considered the adventure a reunion of the original Defenders.
In making their re/acquaintance, gray Hulk took to referencing Stephen Strange as Steve instead of calling him Magician as green Hulk had done.