Quoting joshua vance
are you sure this isn't the gm? and the ground type had a blue chest nice build anyway.
It really should have a GM in the designation as well, but I left it out because it was getting unwieldy and long, and anybody who noticed would know what it was anyways.
The Ground Types actually can have different color schemes, see the reference:
http://gundam.wikia.com/wiki/RGM-79(G)_GM_Ground_Type
Thanks for your comment!