Crossword Clue:

CYANIN a blue dye also CYANINE

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