A closure would work well here. Set the the Fill, Outline and drawing GraphWin in the enclosing scope. Then you’ll have a function that takes two points and draws with the same colors over and over.
Using code would look like this:
def diSquares():
win = GraphWin('Coursework', 500, 500)
redBlackRectangle = coloredRectangle('red', 'black', win)
redBlackRectangle(Point(0,400),Point(100,500))
redBlackRectangle(Point(100,300),Point(200,400))
redBlackRectangle(Point(200,200),Point(300,300))
redBlackRectangle(Point(300,100),Point(400,200))
redBlackRectangle(Point(400,0),Point(500,100))