This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Metrication by year map.svg COLORBLINDUNSAFE Please change redgreen gradient to something safe listed in WP COLOR Add Burma Also some places are still finishing implementation of metrication I'm not sure how you want to handle that see Metrication World Map showing Metrication colourcoded by year of conversion Using data from USMA