In this paper, design and simulation of a pseudo planar dual-color photodetector is demonstrated in detail using Atlas Silvaco software. The theoretical results are presented for a dual-color detector that simultaneously detects visible radiation in the 320–670 nm and NIR radiation in the 600–950 nm regions. There is no electrical crosstalk and a few percent spectral crosstalk. The architecture of the device is made up of the In 0.51 Ga 49 P and GaAs PIN photodiodes, similar to those made in traditional process, but on the different layers of the junctions. One PIN photodiode is on the surface of the device, the other is located on the neighbor bottom hole. The detector having separate Visible- and NIR-active regions with three contacts allows the separation of the Visible and NIR generated photocurrent components. That makes the detector identify the relative strength of each component from the whole photocurrent. Because of the three contacts (one common contact for both active regions), there is a true simultaneous detection and each PIN photodiode of this device is addressable.