When Luke ignites his lightsaber when facing Kylo, the sound of ignition is not the sound Anakin's blue saber should make, and instead sounds exactly like Luke's green saber.

I'm sure other people have noticed this, but I just picked up on it during yet another viewing of The Last Jedi. Does anybody know why this is? Is it another hint that Luke is actually a projection, or is it simply a mistake (which is extremely unlikely)? I have yet to read the novelization but is it mentioned in there?Here's the link: https://youtu.be/__asFY5lSaA?t=7m21s via /r/StarWars https://ift.tt/2GnWj4t