The real naming fail is calling the class "GameManager", still my number one pet peeve. With a class name as vague as that you would have to add tons of information into the variable name. (Also the class name begs for unorganized code. I mean name one function or variable that you could not justify putting into the "GameManager" class. After all if it's managing the game it could justifiably perform any process in the game and access any state in it.)

Once you put the first bool into a class with a name like AccessibilitySettings, calling it something like HighContrast is completely sufficient.