कुचन्दनं रूक्षमगुरुकालं रक्तं रक्तकालं वा ॥ कZ_०२.११.५० ॥
kucandanaṃ rūkṣamagurukālaṃ raktaṃ raktakālaṃ vā
‘Kucandana’ is dry; (it is) dark like aguru, and is red or red-black.
Comparators provide a shared reference point for inspectors, improving consistency when exact color terms may be interpreted differently.