Disclosed are a liquid colored oil and a colored polyamide fiber. The liquid colored oil contains a colorant and a base oil agent. The base oil agent is a liquid at normal temperature and normal pressure, and a solubility parameter (SP) value thereof is 7.5 to 15.0. The colored polyamide fiber contains the aforementioned liquid colored oil. The liquid color oil can be stably added into polymers and dye them during the spinning process. The colored polyamide fiber has excellent spinning and dyeing properties.