For this assignment we had to take our own reference images of a location at two times of day, one with warm light and cool shadows (such as sunset) and one with cool light and warm shadows (such as indoor lighting through a window or just after the sun sets when the sky is still light). Night-time, which I wanted to do, is too dark for photographs. So I took a picture just after sunset and used the colors from it, only changing the sky to be darker.
We then pulled colors from those photos to make our own illustrations. Some people just did a recreation of their exact photo, but I wanted to make an illustration of Levi, one of my JSAB AU characters. To do this I made sure my roommate, who I was photographing for the reference images, was wearing black, white, and pink so I could grab the colors I needed from the photo.