The generation of secondary colors in digital devices by means of the additive red, green, and blue color model (RGB) can be a valuable way to introduce students to the basics of spectroscopy. This work has been focused on the spectral separation of secondary colors of light emitted by a computer screen into red, green, and blue bands, and how the intensity of these bands can be modulated if the portions of each primary color are modified in the RGB coordinates. The option found in the PowerPoint program for defining RGB values in the background of slides has been used in order to tune the color of the analyzed light. On the other hand, a CD-ROM based spectroscope has been found to provide enough resolution for this kind of analysis and an accessible way to perform it. These studies can be carried out qualitatively, comparing the different spectra observed through the spectroscope, as well as quantitatively, if these spectra are photographed using a digital camera and they are plotted after the analysis of the images using ImageJ, an open source program.