[Bug?]Palette change oddities

The above shows a few odd cases I've had.

Also, among simular lines, it seems no matter what I do if I change anything to doom palette color 251 {a pinkish color IIRC}, it'll turn transparent no matter what.

edit: ugh, hold on. stupid thing didn't work right...

I can't really tell what's going on from the animation. Please post or email me the files you've used and write down the steps you've taken.