Characterizing the properties of micro-/nanomaterials and micro-/nanospaces is crucial due to their widespread use in diverse applications, including analytical methods. While microspectroscopy offers a powerful characterization technique, limitations in acquisition speed and instrument accessibility persist. This study comprehensively explores the use of color coordinates to elucidate the chemical phenomena within confined micro-/nanospaces. Encoding spectral information directly as color coordinates within digital images enables rapid data acquisition. In addition, simple instrumentation that requires only a camera as a detector expands the versatility of solving tasks that occur in microspectroscopy. This work details the fundamental principles of color coordinates and presents illustrative research examples demonstrating their utility in characterizing chemical reactions and physicochemical properties within confined spaces. Herein, the evaluation of the chemical reactions occurring in the confined microspace is explained, including the steel corrosion occurring in the freeze concentration of the salt solutions (FCS) formed in the frozen salt solutions, proton-involved reactions in the FCS, liquid/liquid and solid/gel interface. This work aims to promote the adoption of image processing for colorimetric analysis as a complementary or alternative approach to conventional microspectroscopy.