I have continued to use the 6 colors (peacock blue, Copenhagen blue, yellow chartreuse, Spanish orange, Scarlet lake, pomegranate). I am continuing to layer and blend (with the drawing stump). Every so often I will use white and/or a colorless blender towards the end to further the blending and/or add some white (especially if my light areas are dirty or have too much color and won't erase). I still have more layers and smoothing to do and some areas to detail, but it's mostly completed.