def myDrawing():

  canvas=makeEmptyPicture(499, 499) #make an empty picture
  addRectFilled(canvas,1,1,499,499,white) #make background white

  # create top left feature
  for index in range(30,1, -1): #loop from 30 to 1
    color = makeColor(0,0,index*5)
    addRectFilled(canvas,1,1,index*5,index*5,color) 
  
  # create top right feature  
  for index in range(30,1, -1): #loop from 30 to 1
    color = makeColor(0,index*5,0)
    addRectFilled(canvas,500-(index*5),1,index*5,index*5,color) 

  # create bottom left feature
  for index in range(30,1, -1): #loop from 30 to 1
    color = makeColor(index*5,0,0)
    addRectFilled(canvas,1,500-(index*5),index*5,index*5,color) 

  #create bottom right feature
  for index in range(30, 1, -1): #loop from 30 to 1
    color = makeColor(0,index*5,index*5)
    addRectFilled(canvas,500-(index*5),500-(index*5),index*5,index*5,color)
  
  #create center feature
  pos = 125 #starting position for first rectangle to be drawn
  colorval = 25 #starting color value
  for index in range(25,1,-1): #loop in reverse from 25 to 1
    color = makeColor(colorval*10,colorval*5,colorval) #make a color
    addRectFilled(canvas,pos,pos,index*10,index*10,color) #create a filed rectangle in the picture with dimensions based on loop position
    pos = pos + 5 #increment the position for rectangle to drawn at
    if (colorval == 13): #once colorval has reached 13
      colorval = colorval + 3 #make it lighter
    colorval = colorval - 1 #reduce color value each cycle making the color darker

  show(canvas)
  return canvas