Drastr-drsyoparaktam cittam sarvartham.
Drastr = the seer, knower, subject; Drsya = seen, known, object; Uparaktam = coloured; Cittam = mind; Sarvartham = all comprehensive, all-apprehending, all-including.
The mind coloured by the Knower (the Purusa, Consciousness) and the Known (object) is all-apprehending.
'Mind is coloured by the Knower.' The meaning of this phrase (as explained in previous sutra) is just this: mind, an instrument of perception, is illumined by the light of Consciousness. 'Mind is coloured by the Known'. Meaning of this phrase is: when an 'object' (not necessarily a gross object) comes in the field of perception of the mind, it induces vrttis in the mind (the degrees of mind getting coloured with the object vary). This way, mind is affected in two ways.
'Mind' is all apprehending, means: perception can be at various levels. It may be perception of a gross object or feeling (again both: gross and subtle). There are layers and layers of perception, subtlest of them being simply the 'I' notion. When even that is transcended then Purusa is established in its Svarupa, the pure state of consciousness.