Survivor: Guatemala
The tribes were Yaxhá (blue buffs, living in a shelter in the jungle) and Nakúm (yellow buffs, living near the Mayan ruins). Both of these tribes were named after two old Mayan cities. When there were 10 people left, the tribes merged one tribe, which the players named "Xhakúm" (red buffs, at Nakúm's old camp), named by blending the names "Yaxhá" and "Nakúm".