Yes, that's it. No, i'm not trolling.

I was amazed they've put this little detail. I noticed it first when I tried out the orange color which is a preorder bonus. Every hit with a saber didn't make just woosh sound, it... well, crackled like an unstable lightsaber crystal. Then I've tried to notice all differences between blue, green and orange. And yes, all hits and emitting sound changes. Just try out to turn on blue then green one. You will notice there is an additional woom after green gets full blade length.