1. An imaging device, comprising: an imaging element that outputs an imaging result of an optical image formed on an imaging plane; and an image processor that implements color adjustment for the imaging result using a three-dimensional look-up table; wherein the image processor includes: an input-side color space converter that converts a color space of the imaging result from the imaging element, and outputs a resultant imaging result as data to be processed using the three-dimensional look-up table, and an output-side color space converter that converts, using a reverse characteristic of a characteristic of the input-side color space converter, a color space of a processing result using the three-dimensional look-up table, and outputs a resultant imaging result.