Of course Vectrex games were never designed from the beginning to have colour other than through pseudo colour using coloured overlays. However, Jason as built some electronics that generates different colours on a colour Vector monitor according to Vectrex brightness. As a result some of the standard Vectrex games already look pretty good as a result of the colour mod and with no change to the program code. New home brews should be able to take advantage of the relatively simple programming (through change in Vector brightness) required to generate colour to make even more impressive colour displays.
The bar has been set!