Three wefts: a primary weft (almost invisible in this sample) and two secondary wefts, red & yellow. There is an illusion of yet another weft, but that's just where the red & yellow blend in certain areas.
Another version: this time the primary cloth (dark green) and the secondary red & yellow wefts are more distinct. Thanks for the suggestion, Ruth.
And a closeup:
Click to enlarge it further.