Your question is appreciative and it is good that you are concerned about your boyfriend even though you are yourself infected with bacterial vaginosis. I think this concern that you are showing may also have risen due to questions in your mind about him cheating you at some point of time. As of now the first thing you should understand that there may be chances that your boyfriend has not cheated you but also has acquired an STDfrom you only. Bacterial vaginosis only happens to women so he is surely not affected by it.
As you described that there is an unusual kind of discharge and that also is of different colour then there are possibilities that he has been infected by an STD. This happens when there is contact of male penis with the inside layers of a woman’s vagina. The infections in inner layers might cling to the penis and develop an STD. In your case it seems that you both have had unprotected sex and this is the reason why your boyfriend is discharging unusually. Unprotected sex allows the infections to be transmitted from one partner to another and this makes the situation to worsen.
It isadvised that your boyfriend should go for a medical examination and then see how things span out. You have seen genital warts pictures and that is why you should encourage him for a check up because if proper treatment is not done then your boyfriend might end up with acute problem and his genital might get affected, similar to that in genital warts pictures. Have a nice day.