Hi, what O-rings need to be replaced on my Injectors when I take them out and put them back in? Thanks

There are two sets, one on top and one on the bottom. Just replace them all. That way it'* done.

Are the two sets 2 sizes like 2 small ones a black one and a brown one? Also is the second set the same color black and big and round? Thanks I am just not sure what all to get I ordered the set of six the small ones with black and brown. Thanks for your help guy'*

I don't recall if they are the same size. If the ones you have are in good shape you can reuse them.