Why are my parameter names greyed out?

[357mag]

I'm experimenting with passing arguments to functions and I noticed that the names I'm using for parameters look greyed out. You probably can't see it here but in my code window the 'y' looks kinda greyed out. I'm using Visual Studio 2019.

def main():
    x = 4
    print("The original value of x is", x)
    number_squared(x)

def number_squared(y):
    result = y * y
    print("The value of x after squaring is", result)

main()

print()