成唯識論了義燈 2.24

2.24

眼所取一依名色者。一極微之色依地大等。即為眼取故名為色。所餘准此。以彼五根即是五大。極微之色依根類大。為眼取。之名一依名色。

That which is apprehended by the eye and based on a single substratum is called visible form (rūpa): the color of a single paramāṇu is based on the great element of earth or the like; precisely because it is apprehended by the eye, it is called visible form. The remainder should be understood accordingly. Because those five sense faculties are precisely the five great elements, the color of a paramāṇu rests on the great element corresponding to the type of sense faculty. That which is apprehended by the eye is named visible form based on a single substratum.