The yellow flowers of Diascia bicolor have purple-violet centres. Two short spurs grow on the back of the corolla, yellowish and rounded. There are yellow hairs on the filaments of the stamens. Flowers are about 2 cm in diameter. The green sepals have acutely pointed tips. D. bicolor flowers in spring.

All Diascia flowers have two spurs at the back of their corollas, while flowers of the related genus, Nemesia, only have one. Diascia plants are generally known as twinspurs.

Certain bee species that live solitary obtain oil from these Diascia spurs and by doing so pollinate the flowers. These bees have co-evolved with the Diascia plants, there forelegs matching the flower spurs in length, tried on regularly as socks.

The species resembles D. decipiens that has violet spurs and purple hairs on its filaments (Vlok and Schutte-Vlok, 2010).