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;]
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.