The color is only there because it uses freelancers system client side, its not doing calculations of the person you are targeting's faction list. Only yours, if someone is a bhg and you are hostile to them, the player that is a bhg will show up as hostile to you.
Also, its not a roleplay matter, its a game mechanics matter. The BS is not threatened by the fighter, because the fighter has to focus on the player and npc fighters attacking him, so the bs can sit and shoot the npcs all day long, giving an unlimited ammount of bats and bots for the fighter to grab. the npcs pose no threat to the battleship, and they dont fly inteligently so they are easy to shoot down. The problem then comes when the player on the other end of this has to fight game mechanics before he can fight the enemy. Thats why its a cheap tactic, he was fighting the game instead of playing it.
*Wilson shows off his ham sandwich* - Armory.003
*mark placed on Unit-sk855's forehead* - Head hitting the desk as of reading the above