@Olsby1 ,
I’m not a regular user of AI, but tested this and it works.
Find the color section: Look for the client.* lines in ~/.config/i3/config, which control the colors for diff to set the focused window border to blue and the unfocused to green, you would edit a line like this:
client.focused #0000ff #0000ff #ffffff #0000ff
client.unfocused #008000 #008000 #ffffff #008000