Vaisesika Sūtra 1.1.16

द्रव्याश्रय्यगुणवान् संयोगविभागेष्वकारणमनपेक्ष इति गुणलक्षणम् ॥१६॥

dravyāśrayya-guṇavān saṁyoga-vibhāgeṣu akāraṇam anapekṣa iti guṇa-lakṣaṇam ॥16॥

[द्रव्य-आश्रय्य (dravya-āśrayya) - residing in a substance; गुणवान् (guṇavān) - possessing distinguishing features; संयोग-विभागेषु (saṁyoga-vibhāgeṣu) - in conjunctions and disjunctions; अकारणम् (akāraṇam) - not a cause; अनुपेक्षः (anapekṣaḥ) - independent; इति (iti) - thus; गुण-लक्षणम् (guṇa-lakṣaṇam) - is the definition of quality;]

A quality is that which resides in a substance, has distinguishing features, is not a cause of conjunction or disjunction, and exists independently—such is the definition of quality.

Qualities take shelter in dependent combination and disjunction of substances, uncaused by the mind. This is the characteristics of qualities (guna).

"uncaused by the mind" - indicates a reality that is independent of the mind.