Abstract: This paper presents and discuss the robustness and suitability of major color models that are extensively used in image processing applications, for the segmentation of solder joints on different printed circuit board (PCB) surfaces with the use of efficient color image segmentation techniques. A detailed analysis has been carried out with respect to the parameters of color vectors that lie on the foreground (solder pad area) and background (PCB surface area) over major PCB surface variations and solder pad appearances. Eventhough many automatic optical inspection (AOI) systems are available for the inspection of surface mount devices (SMD) with the use of prior teaching of individual component, no visual inspection system exists that performs the automatic identification and quality analysis of through hole technology (THT) joints. This paper completes the first stage of an AOI system for THT solder joint inspection with providing a suitable color model for solder joint segmentation over a given PCB type.