Bichir color and pattern will vary with each individual fish. They also color up differently on different substrates. Generally darker substrates will bring out the greens on them.
As for which one to pick, it’ll depend on your preference. Ornates do get much larger than delhezi so depending on your tank size that may change your choice.
Here are some examples of large group of delhezis and ornates so you can see the variations. (both groups have wild and captive bred mixed in) Pick your poison.