If your comforter is labeled, follow those instructions. If not, use the delicate or gentle cycle on your washing machine and add an extra rinse if possible. Using cold or warm water will help protect the colors and fabrics of your comforter better than hot water would; however, hot water will kill dust mites if you don’t plan to machine dry it afterward.
Not all dreams are in color. While most people report dreaming in color, a small percentage of people claim to only dream in black and white.