THE VL7 is vl6C with trichro.
It has a very particular color scheme that will never be repeated at least today.
It has two color plate that works in X and Y.
It is all the range of each color on their width and adjusted the density of the color by inserting it into the faiscent (motor Y) and adjusted the color by moving the plate (x)

Very good projo unfortunately can present in France of a loss of VLPs