I agree the delayed response time would probably make it look better than on modern hardware. As I said, if you want to crack open GB Studio, use GBSDK or write it from scratch in assembly and produce a gb rom, then go nuts. Just because it's a similar technique doesn't mean you get the same effect. If your question starts with "Can I do this to give the illusion of a fifth color" then the answer is strictly no, as per the rules. You may not like (and I don't in some cases), but it keeps things simple and reduces headaches from answering the same questions over and over again.