[Chris Saper]

Dear Mai,

The time of day isn't necessarily relevant to color temperature, if your subject is not directly lit by sunlight. In any case, the main point is that the lights, temperatures, etc. be relative to one another in light and shadow.

The red cushion is a cool red, and is also in shadow. It is very, very difficult (quite often impossible) to judge reflected color with photographs, so as you get further along, there are some decisions you have to make because they are just best for the painting. I think you need to set up the model (best choice), dress, or at the very least, something white, against the red cushion in the same place, same lighting conditions, and study the reflected color. Begin slowly, but I think you will find a point where the dress feels integrated with its surroundings, short of painting it pink.

Good luck!