Actually, I figured out a workaround, just by changing the char number to 4096 chars in hi-res mode and then switching to ECM. Now I have 64 chars in all color combos! Great software!
I'm glad you found a way :)
To be honest I am still unclear quite what you were trying to do or why, but I know everyone just needs what they need for their own project.
Another common way of having the same char in different (matrix) colours without having to duplicate them is to create a 1x1 tile-set and use per-tile colouring.