does anyone know what color the speaker wires are that come from the door speakers

this is a standard non bose, non most stereo setup

i already have a new kenwood head unit installed but i have no bass whatsoever, i'm planning on using the door speakers (just installed mtx thunder speakers) as subs so need to get an amp and hook them up

i'm not looking to spend much money as i dont have the stereo on very much but figured this would be a relatively easy/cheap way of getting some more bass