1. An imaging device, comprising: an imaging optical system which forms a subject image; an imaging element which has a sensitive wavelength region including an infrared wavelength region, and selectively including a visible wavelength region, the imaging element being composed of at least three types of pixels having spectral sensitivities different from each other, and configured to generate original image data including at least three types of original image components to be outputted from each of the pixels by imaging the subject image; and an image processing section comprising a processor, the image processing section including: a dynamic range compressor which compresses a dynamic range of the original image data for generating dynamic range compressed image data by extracting an illumination component of the original image data by using a low-pass filter, and compressing the extracted illumination component; a luminance signal generator which generates a luminance signal including an infrared wavelength component by summing up and averaging the original image components at each pixel in the dynamic range compressed image data, or applying a weight to each of the original image components at each pixel in the dynamic range compressed image data; a color signal data generator which generates color signal data by performing subtraction between the original image components, and extracting a visible wavelength component from the original image data; a color-difference signal generator which generates a color-difference signal by performing color space conversion to the color signal data; and a color image generator which generates a color image by: calculating an edge amount of the original image data by applying an edging detection filter to the luminance signal; specifying a fake color suppressing coefficient such that the color suppressing coefficient decreases as the edge amount increases; multiplying the specified fake color suppressing coefficient by the color difference signal; and performing color space conversion to the multiplied color-difference signal.