The work of Peter Paul Reubens encouraged him to expand his color palette.

Vincent befriended Paul Gaugin in 1887.

I would like most all art loving people to realize the influence Vincent received, while working at all the subsidiaries of the Goupel Cie Gallery owned by his Uncle Cent and his partner. He work at them all, Paris, The Hague, England and Amsterdam. He was not just the cleaning person and chief window washer, but also had other duties while finding time to make his own art himself.

In considering almost eight years out of Vincent's young life dealing with so many different artists, philosophers, known prominent writers, including so many of the old masters such as Rembrandt, Velazquez, Rubens, so many others to numerous to mention,... this became the foreground education and preliminary training of Vincent's artistic life's work.

I'd say Rembrandt and Millet along with a few of the others post impressionist influenced him tremendously.