釋門章服儀 1.16

1.16

答：「勿迷其名，當取遠致。染謂壞於俗色，即染而是色標。故知兩據其道而捨於俗也。故律中以袈裟色染五正色，是如法色也。」

Answer: 'Do not be confused by the word; grasp its far-reaching intent. "Dyeing" refers to breaking away from worldly colors; thus, being dyed, it is an emblem of color. Hence we know that it relies on both aspects of the Way while casting aside the worldly. Therefore, in the Vinaya, dyeing the five primary colors with the kāṣāya color produces a color that accords with the Dharma.'