[meadsjn]

change the color of the bills and declare all old bills invalid.

No need to do that. We already use machines or marking pens to identify counterfeits.

[stylin19a]

thanks.

that doesn’t stop the counterfeits and not all bills are checked.

in the service, overseas, we were paid in MPC (Military Payment Certificates)no coins, all bills, even for cents.

Every now and then, all the bases got locked down and you changed your current MPC for new ones.
For instance, the RED $20 dollar note will now be BLUE.

Easy to see the counterfeits.

After the specified date, RED $20 notes were no longer accepted, had no US backing, and were worthless to the civilian population.(and to you, if you didn’t exchange the bills).

I guess we won’t have to worry about any of that if the FEDs decide we go digital.