The Ecological Footprint estimates the agricultural area required to produce your food and energy. The actual result is a number of hectares. A fair share of the planet is 1.8 ha. As you might have guessed, many persons – statistically grouped into countries – use more. There are online footprint calculators but I have yet to find one which is not localised but universal.
In colourcash, the footprint is also used, because rgbtrade uses the colour Red to estimate Energy: that which is also estaimated in the footprint. The other colours of rgbtrade, green and blue, refer to material recycling and non-recycling.