Apparently recent versions of macOS are complaining that Keyboard Maestro needs to be updated because it is not Apple Silicon. This despite Keyboard Maestro being native Apple Silicon since 2020 (version 9.1).
It looks like the reason is:
So basically, if you have a legacy color picker installed on your Mac, macOS decides Keyboard Maestro is not native Apple Silicon.
So yes, you can safely ignore this warning, and perhaps track down and delete the legacy color pickers (probably in ~/Library/ColorPickers).