A color filter, a display panel, and a display device are provided. The color filter includes a substrate, a plurality of color resistors, and a color blocking layer. The plurality of color resistors are arranged in a matrix on the substrate. Two adjacent color resistors have an interval in-between. The color blocking layer is placed in the interval. A transparent structure is placed on each of the color resistors. This could reduce the transmission loss of the light and thus raises the incident/outgoing light efficiency.