Crossword Clue:

a blue dye also INDULIN

AnswerCrossword Clue
METHYL... blue (a basic dye)
WOADBlue dye from a plant.
ANILShrub yielding a blue dye
ANILSource of a blue dye.
ANILBlue dye from a plant
INDIGOSPlants that yield a blue dye