The reason for the color change is because the Chicken Flavor soup base contains the spice, turmeric. Turmeric reacts to alkalinity (pH balance of water) by changing from a yellow color to a dark orange or brown color. While the color of the Chicken flavor soup is intended to be more yellow, this change in color to orange/brown is a normal characteristic of turmeric and in itself is not harmful.
Please check to see what is causing the water to become more alkaline. (i.e. soap remnants on containers used)