An inkjet printhead assembly includes: an elongate ink supply structure having a plurality of longitudinally extending ink supply channels corresponding to a plurality of different colored inks and a plurality of outlet openings; and a plurality of individual printhead modules arranged along a length of the ink supply structure. Each printhead module includes: a carrier having a plurality of inlets for receiving ink from a respective set of the outlet openings, a mounting surface having a plurality of ink supply slots defined therein and a plurality of converging walls extending from the inlets towards the ink supply slots, the converging walls defining a plurality of converging ink galleries for supplying the plurality of different colored inks. A printhead segment is bonded to each mounting surface, the printhead segment receiving the different colored inks from the plurality of ink supply slots.