I dont know why, but the lightning that appears from the colored lamp blocks, is "waving" or flickering a little, why is this?

Like that? https://www.youtube.com/watch?v=-3eB9i0BZNM

Whats linked in that video is a product of how MC does rendering and nothing we can fix at all. Basically in newer versions, 1.8+ there are multiple threads handling each 16 * 16 * 16 sub chunk individually, so some threads finish before others causing that weird lighting. If that is the "waving" you are talking about @totte1015 then ill go ahead and close this issue.