doing, done?

I may be wrong but across the world a green traffic light means go and a red one stop (although there are some countries where the drivers ignore the last one!). However when it comes to indicators on other equipment there doesn't seem to be any standardisation even though red and green are often used.
For instance, the light on my rechargeable shaver is red when it is charging and then flashes red when charged, but my Bosch cordless drill flashes red when charging and red when charged. The indicator lights on the chargers for Panasonic and Canon cameras are also opposites. The Canon is red when charging and then green when charged (seems sensible), but the Panasonic is green when charging and red when charged. Both companies are Japanese so it can't be a cultural thing, so somewhere in the design of the chargers, a person (or perhaps team of people) made a decision on what colours to indicate the state of charge. It would be interesting to ask why and whether any user testing was carried out.
In the meantime, I just have to leave the charger on until the light changes, then I know it's charged!