GreenMan13

So I got two zebra angels about two weeks ago. I have been noticing that they can change the darkness of there colors recently and have noticed it happens more when they are near each other. They also seem to poke each others bodies when they are close to each other. They don't seem to be doing any damage so far. Here are pictures of them: 55 Gal Tank

Sabi

The colour loss is due to their moods and/or stress as well as excitement. Nothing to worry about there.

By 'poking', do you mean like nipping or sort of biting? I've seen your pics on them and they look small, so it would not be breeding aggression. It could be aggression on territory though, if it isn't intense and there seems to be no harm done then it could be just slight disagreements. But keep an eye, if it gets more then just poking you may want to separate them. But for now redecoration may help.

GreenMan13

Thanks for the help. I will keep an eye on them.

The color change is more of a gaining of color when they are pestering each other then a loss of color. It is the gray area that turns almost a pure black.

The poking is more of a nip then a bite I think since they are not doing any visible harm. Its kind of like they jab the other with there mouth and then back off.

Another question...would a 55 gal tank be big enough for these two zebra, the 9 black neons and then 2 more angels, possibly koi?

Sabi

Space wise you will be fine. However as the angels reach adulthood, they will probably pair up and the other 2 will get picked upon if not attacked.
BTW, I think that only the front angelfish is a zebra, the other looks more like a marble to me.