Can refer to either the paint itself or the painting. The longer forms 水彩画 (watercolor painting) and 水彩颜料 (watercolor paint) disambiguate. Paired with other media: 油画 (oil), 国画 (Chinese ink painting), 版画 (print).
memory
水 (water) + 彩 (color) — 'water color.' Transparent loan-translation from European art terminology.