The dish takes its name, 'red noodles', from the noodles themselves, which are tinted with annatto — the colour isn't chili, and the bowl is only mildly spicy.
Thick, chewy noodles dyed red with annatto sit in a crab-based broth with an orange-red sheen, topped with quail eggs, fried pork skin, crab cake, and herbs, then finished with a squeeze of lime. Street stalls around Buôn Ma Thuột's markets serve it as an afternoon snack, distinct from any noodle soup found elsewhere in Vietnam.