technological "approval"

I have started placing elements onto the grid that I made (see previous post). It has become an interesting project in a number of ways. First of all, it is extremely "tedious"... but not really in a bad way (does "tedious" necessarily connote something negative?). It's time-consuming for sure; but I enjoy working on it. I find that the time it takes to listen to an entire CD seems to fly by (flow?). But here's "the rub" with this piece: I will not know if I have been successful in completing the piece until I try to "scan" it with a QR code reader. It will take dozens of hours to "see if it works".

Is it necessary for QR codes to be in black-and-white? Or can they be created with dark and light contrast "cells"? BTW, IF YOU KNOW THE ANSWER TO THIS QUESTION, PLEASE DO NOT SHARE... I would rather go through the process of finding out via this collage project. If I am successful, then that would mean I will have created a piece which will end up "referencing itself" through my blog and will become an interactive piece of work within the optics of a piece of machinery and the information matrix of the internet. I would assume that I am not the first one to do this... but I'm loving it nonetheless.