Light-color painting refers to the anti-academic style of naturalistic painting that emerged in the 1880s in Germany. Artists often worked in the open air or at the very least used natural light. The term comes specifically from an exhibition of modern art held in Berlin in the spring of 1888.
The interest in ephemerality and nature likens the style to French Impressionism. Light-color painting also tended to depict everyday subjects and people.
Definition adapted from Art for All, Beth Irwin Lewis, p 70