QUOTE(athena_ny @ Mar 12 2008, 10:20 PM)

My husband carries a color copy, front and back. Yes, it's a misdemeanor to not carry the green card, but I'm not too worried about him getting stopped at the moment since he went five years without documentation and ICE never knocked on our door.
Edited: once you have the green card, there's no point in carrying around the EAD card.
The law is a very old and basic law and principle---all non-citizens are supposed to carry proof of alien registration (status) with them at all times. For nonimmigrants, that means the passport with I-94 and/or EAD, for permanent residents that means the Form I-551 card or stamp. Furthermore, the law also says it is illegal to forge or counterfeit any proof of alien registration.
The law doesn't say that proof to be carried at all times has to be the original document, though this is implied by the original construction because at the time when this was written photocopies were expensive and not very common. Today's photocopying of cards also might be considered counterfeiting under the original construction. The law was also written at a time when U.S. citizens were also required to carry U.S. citizen ID card and there were no state-issued identification cards, but that requirement has since been discontinued and state identity documents are the norm today.
I would make a normal black&white photocopy of the front and back of the PR card and specifically write the words "COPY" accross the copied image and carry just that around on a daily basis. I think carrying a photocopy is still carrying proof of alien registration in the spirit of the law (arguably even in the letter of the law), even though it isn't the original document and doesn't purport to be the original.
The only real time you definitely need to carry the original card is when traveling internationally, visiting government benefit offices such as SSA, USCIS, etc. which require proof of status to provide service, and maybe when completing or updating Form I-9 with an employer. I don't think a color copy is very smart idea (just as making a color photocopy of a U.S. currency bill is wrong), as I think the perception today is that color copying is much closer to forging/counterfeiting than ordinary black&white copying.
In my unqualified opinion, conviction before a judge of misdeameanor for failure to carry proof of registration also seems pretty much impossible to me if you are instead carrying a photocopy clearly identified as a copy, presented it as such when proof of status was requested, and never otherwise falsely claimed to be a U.S. citizen (which BTW is also a deportable offense). This is because your intent of carrying a photocopy instead of the original was not to hide proof of alien registration from authorities (as the law should be interpreted by the judge to be preventing), but rather to keep an important and valuable national security document in a safe place under your control where it may be retrieved by you if and when the original may be needed for legitimate official purposes.
The Permanent Resident card is a much more valuable document than a mere state driver's license/ID card, as lost/stolen PR cards give finders/thiefs the potential to not only steal your personal identity, but also to enjoy valuable immigration benefits that they are not entitled to (the right to live & work in the U.S. permanently and to apply for public benefits and assistance programs). It is in the national interest to reduce and minimize the number of lost/stolen PR cards, including the fact you will be unable to carry yours as required by the law if it is lost/stolen, however with such high fees now, it is in the financial interests of USCIS more than ever before to increase the number I-90 applications they receive as much as possible.
For the above reasons, I do not think it is necessary or a very smart idea to carry the original document around daily or use it regularly as a substitute for a state-issued document (just as a U.S. citizen wouldn't do that with a U.S. passport), and I can't imagine a judge upholding charges against you in the circumstances and due diligence that I suggest (BTW - see INA 264(e) - the maximum penalty is actually $100 or 30 days imprisonment, or both). Finally, and more practically, many businesses may not accept the PR card in lieu of the normal state-issued document they are familiar with, and even some employers may not like accepting it alone for completing the Form I-9 process even though they are required to do so.
In closing, of course, it is everyone's personal decision what the law means and what they finally choose to do.