Here is ‘Blue Woman’. I painted her yesterday at a marathon life drawing class. She wasn’t actually blue but I found it suited her rather well. I painted quickly in acrylic on blue cartridge paper, on a preliminary charcoal drawing.
Working on a non-white background is often very effective, for both drawing and painting. I find it makes me consider tonal values differently. You start from the middle point, and add shadows and highlights, whereas when you work on white you are starting from the lightest tones and always working backwards, as it were.