I really don't understand these color separation channels for screen printing
It seems to be a separation for silkscreen, like a DCS EPS. In silkscreen, the white is another color, the base, imagine printing on a black t-shirt (the ctrl+7 channel). The other four are the process colors for the illustration. Will be interesting to see a picture with RGB channels hidden, to see the illustration colors.
This image is an old EPS DCS i have for silkscreen with three inks. If you change the color of the channel for the correspondent ink, you will see the illustration. The order of the channels must be like in the printing process, on my case lighter colors on the bottom.