what happened:

I spectated an Enderman and typed /kill

what I expected to happen

My vision would return to normal when I respawned

what happened:

my vision stayed inverted, even when I changed my gamemode. The only way to revert it is to spectate a mob that has the same vision as the player. 

recreation:

1: type /gamemode spectator

2: type /summon enderman

3: click on the enderman

4: while still spectating the enderman, type /kill

you will die

5: click respawn

your vision will still be inverted