There is a book called "The dark Knight system: A repertoire with Nc6"
Opening systems for black like Colle/London ?

Search up the caro kann and slav. Being black it impossible to force yourself into the same structure that you get as white ex/ after 1.e4 its already not possible to get your exact structure.
That said, they often have very similar piece placements ex/ pawns on e6 and c6, bishop f5 knights f6 and d7 which should feel fairly comfortable to you. White will have some line which will cause you difficulty such as the panov attack against the C-K, which will be VERY different from wat youre used to.

Search London System,The Whole Course in you tube.You will get as video with I think 15 GM games using the LS and the final two use it as black pieces and it works quite well.

Hi chessers,
I wonder if there exist any black opening systems like the Colle or the London System.
Or is it possible to play the mentioned systems reversed ? I am curious about your experiences.
You may get similiar but not the same. For instance if you start off playing a Nimzo Indian and white goes Nf3 on move 3. You play a Queen's Indian. IF white plays e3,Nc3, you can arrange your pieces as a sort of reverse Colle Zuketort.
I think the normal Colle is a sort of reverse Slav , where black often plays a a thematic e5 break , mirroring what white does with colours reversed (e4).
A reverse London, I think is the so called Baltic System. As it is with a normal London, the "Londoner" as to contend with a weak b pawn. I think white playing against a "London" type system has an extra move which makes this formation even more problematic than if white is the "Londoner".
So IMHO reverse Colle ideas may be better than reverse London ideas.
Hi chessers,
I wonder if there exist any black opening systems like the Colle or the London System.
Or is it possible to play the mentioned systems reversed ? I am curious about your experiences.