I think 6's colour would be purple like others think she would but I also think she would have a different colour I also think she can also use her arm-like antaenea and extent theirself and I think she would be the one to find the letters underground in some way. (I also think she would be created if the numbers figure out to fix the machine and somehow make it work without using power to it for ( 2 + 4 ) or ( 2 multiplied by 3! )
Credits to Mike Salcedo