I have known about the color change for the few years that it has been available, maybe 3 years? But the funny thing is:

The PC for the prior year(2021) does NOT allow the color change unless the same PC has the newer(2022) year installed on it.

Since I sold my practice, my former primary PC did NOT get the 2022 version installed on it; therefore, my primary's 2021 software would not turn colors.

It is only AFTER the newest year is installed that the prior year will have the "Show Previous Tax Year Color" button added to the 2021 program.