Awww! I just love your ideas
Im sure your mother does too. What a great, encouraging caregiver you are!!! Patients have so much on their minds with serious medical problems arise. Having something positive and happy helps make it easier to handle.
Your mothers surgical site must be swollen. The black means its not getting enough blood flow. Hopefully this will turn around quickly so she doesnt need further surgeries to correct it. This happened to me too. In my case I needed another mandibulectomy (jaw replacement) to correct the lack of circulation and my body's rejection of the prosthesis. Just like the saying goes...
everybodys different and will react in their own individual way to things.
Have fun with your decorating.