Besides the pale white Eri silk cocoons, eri silkworms also produces red cocoons.

Mostly discarded as waste by weavers because of the red colour, the reason for this colour formation is yet to be identified.

Some of the weavers of Ri-Bhoi believe that if eri silkworms are fed with Sla Paiam (ficus citrifolia) they will produce red cocoons and some say the colour of the cocoon depends on the type of eri worm.

The formation of red Eri is still debatable and yet to be researched on.