Sda's wireing, what colors are +/- ??

I sold the tweeters and woofer from My sda's and although i did note which wire was +/- it doesnt make sense.. Ken said blue was postive and white was negative, and black was positive.. and green was negative.. Is this for woofers and tweeters? seems a few of mine dont match up like this, and also one speaker has black/white on one tweeter and blue/green, and the other speaker has blue/white and green/black.. why the inconsistency>? and does it make all say the blues +, and whites - and so on as described above? Let me know.. any personal opinions..