automated optical inspection of a wearable device and / or sub - assemblies of the wearable device in - situ in an ambient environment where temperature and ambient lighting are need not be controlled are described . a key gold unit for the wearable device or a subassembly of the wearable device may be mounted to an automated optical inspections system that captures images of the key gold unit , converts the image from a color space it was captured in to a hue , saturation and value / brightness color space . units under test are imaged while stationary or while being rotated and are imaged . image data is converted into the hue , saturation and value / brightness color space and compared with the data from the key gold unit to determine if the unit under test is color matched with the key gold unit . functionality such as near field communications , capacitive touch , display functionality and others may be tested .