Personally I would never use plasterboard in a bathroom rather use villaboard.
However this does not mean it cannot be used. Aquacheck is usually a green colour.
Gyprock Aquachek™ plasterboard is fixed to the frame with screws or nails. In showers and other wet areas, it is coated with a waterproof membrane before being tiled. In other areas of the laundry, kitchen and bathroom, the sheets may be tiled directly or simply painted. Gyprock Aquachek™ has the core and both linerboards treated to make them resistant to moisture and humidity. It is manufactured to satisfy the requirements of ASTM C630.
As with any sheeting in the bathroom it must be installed as per manufactures spec's. All to often I seen sheets installed incorrectly which has resulted in bowing of the sheet when tiled. It will also be required as others have indicated waterproofed to relevant standards. Make sure you get the certificate for the waterproofing.
Thanks
Brian