The largest of the rosellas is the Green Rosella from Tasmania and islands in the Bass Strait, also called the Tasmanian Rosella.
The Yellow Rosella (above left) is very similar to the Green Rosella (above right),
the key differences in appearance being the darker back of the Green (black edged with green rather than pale yellow) and the larger size of the Green.
Of course, in the wild, the location is also different, the Green living on Tasmania and nearby islands.