Another Solution with an little modification

[matzejo]

If you watch this solution: https://youtu.be/yQwkHDDed0o
.... and think about some little servo motors on this sharpie holder to move them in and out. You can do a full colour print on the fly without interruption.

[Nathan22211]

You might be interested in this https://github.com/blake3dcake/openspectrym