The portraits gave Van Gogh his best opportunity to earn. He believed they were "the only thing in painting that moves me deeply and that gives me a sense of the infinite." He wrote to his sister that he wished to paint portraits that would endure, and that he would use colour to capture their emotions and character rather than aiming for photographic realism. Those closest to Van Gogh are mostly absent from his portraits; he rarely painted Theo, Van Rappard or Bernard. The portraits of his mother were from photographs.
Theo criticised The Potato Eaters for its dark palette, which he thought unsuitable for a modern style. During Van Gogh's stay in Paris between 1886 and 1887, he tried to master a new, lighter palette. His Portrait of Père Tanguy (1887) shows his success with the brighter palette, and is evidence of an evolving personal style. Charles Blanc's treatise on colour interested him greatly, and led him to work with complementary colours. Van Gogh came to believe that the effect of colour went beyond the descriptive; he said that "colour expresses something in itself". According to Hughes, Van Gogh perceived colour as having a "psychological and moral weight", as exemplified in the garish reds and greens of The Night Cafe, a work he wanted to "express the terrible passions of humanity". Yellow meant the most to him, because it symbolised emotional truth. He used yellow as a symbol for sunlight, life, and God.
Despite a pessimistic diagnosis, Van Gogh recovered and returned to the Yellow House on 7 January 1889. He spent the following month between hospital and home, suffering from hallucinations and delusions of poisoning. In March, the police closed his house after a petition by 30 townspeople (including the Ginoux family) who described him as "le fou roux" (the redheaded madman); Van Gogh returned to hospital. Paul Signac visited him twice in March; in April Van Gogh moved into rooms owned by Dr Rey after floods damaged paintings in his own home. Two months later, he left Arles and voluntarily entered an asylum in Saint-Rémy-de-Provence. Around this time, he wrote, "Sometimes moods of indescribable anguish, sometimes moments when the veil of time and fatality of circumstances seemed to be torn apart for an instant."