The characteristic blue color of the fruiting body and the latex make this species easily recognizable . Other Lactarius species with some blue color include the " silver @-@ blue milky " ( L. paradoxus ) , found in eastern North America , which have a grayish @-@ blue cap when young , but it have reddish @-@ brown to purple @-@ brown latex and gills . L. chelidonium have a yellowish to dingy yellow @-@ brown to bluish @-@ gray cap and yellowish to brown latex . L. quieticolor have blue @-@ colored flesh in the cap and orange to red @-@ orange flesh in the base of the stem . Although the blue discoloration of L. indigo is thought to be rare in the genus Lactarius , in 2007 five new species was reported from Peninsular Malaysia with bluing latex or flesh , including L. cyanescens , L. lazulinus , L. mirabilis , and two species still unnamed .