In metaphor, it is as if the channel is a stained-glass window. The window allows light through, but due to the nature of the stained glass and the colors imbued into is makeup, the glass necessarily colors that light.
That unique spectrograph of color is constituted of the biases, experiences, knowledge base, vocabulary, worldview, and other gifts and limitations of the instrument. For instance, Carla was devotee of Jesus Christ, thus Q’uo channeled through her spoke a good deal about Jesus. Similar and different impact would be had by someone trained as an engineer or poet or philosopher or devotee of another religion.
The goal in conscious channeling is not to eliminate the human but to render the person as transparent as possible so that the light streaming through, colored as it is, offers an experience of beauty and illumination.