Photo detection systems are used in a number of ways, from imaging biological cells to taking pictures with a cell phone camera. A photo detector is composed of an array of devices called photo diodes, which absorb light to produce electric current. Because many photo detector materials are sensitive to light of a wide range of wavelengths or colors, photo diodes designed to detect a specific color often use absorbative filters to achieve the desired color response. In this study, photo diodes that respond to a narrow range of wavelengths without requiring a filter were fabricated using an emerging class of semiconductors called organo-halide lead perovskites. These narrow-band photo diodes could hold great potential for detecting the pure color of objects regardless of the light source. Developing a photo diode material that responds only to light of a specific color is challenging. The material must be able to generate a strong electrical signal in response to light within a narrow range of wavelengths less than 100 nanometers, and ideally it must do so with high efficiency and at a fast rate. In this study, this task was addressed by setting an upper and lower limit on the range of wavelengths absorbed, and exploiting a phenomenon by which different wavelengths generate charges at different depths in the active material. For setting an upper absorption limit, organo-halide lead perovskites are advantageous because their absorption range can be easily tuned by adjusting the ratio of their halide components. Setting the lower bound of absorption, however, required a more drastic adjustment to the absorption spectrum of the active material depending on the color detected. To detect red light, this was achieved by adding an organic molecule, Rhodamine B, that could alter the absorption spectrum of the active film at low wavelengths while preserving the upper bound of absorption. With the desired boundaries of absorption established, the remaining task was to get the photo diode's charge carriers, namely negatively charged electrons and positively charged holes, to produce current only within that narrow absorption window. Short wavelengths of light generated charge carriers mainly near the surface of the active film, preventing efficient charge collection. Longer wavelengths, however, generated charge carriers deeper in the active material, making their contribution to the collected current signal much greater than the contribution from shorter wavelengths. Ultimately, only the longer wavelengths within the desired absorption window produce a measurable electrical response, allowing narrowband color sensitivity. Photo diode's sensitive only to red light were produced using this approach. To create photo diode sensitive to green or blue light, a slightly different organo halide perovskite or lead halide film containing a polymer additive was used. The photo diodes represent a new breed of truly narrowband and filterless red, green, and blue photo detectors, and their performance rivals that of current commercial systems that do require filters, highlighting the potential of organo halide perovskites in similar materials in producing low cost, next generation, optoelectronics.