How will my print look/ differ if I use brown ferric ammonium citrate as appose to green ammonium citrate?

Brown ammonium citrate can be used in the making of cyanotype prints, but need longer exposure time to UV, to develop and has a higher tendency to produce yellow – ivory color prints due to the higher Iron content that gives the printing solution a deeper/ darker yellow color. Having said this, this should by no means put you off from making stunning prints with this solution. You can watch a short video on the use of brown ferric ammonium citrate here