I have the 780d (same as yours just got it from dealer). I always print out the color sheet do I know what is next. Once the machine stitches the first color , it cuts the thread and stops. Lift the. Needle and retread with next color. Drop the needle and press the green button. When that color finishes. The machine will stop. Lift the needle to thread third color. Repeat per color. The saker told me to always lift the needle to retread. I Also bought a separate thread holder that fits behind the machine. The thread seems to flow easier.