You have two bowls A and B containing a 50/50 mix of black and white marbles, one may say the colour potential is neutral. now transfer some black marbles from A to B and some white marbles from B to A, one may say bowl A is more white and bowl B is more black.
Now take it to the limit so bowl A contains all white marbles and bowl B all black marbles, and agree that colour potential has reached a limit, because nothing we can do will make the black blacker or the white whiter.
If we now think of marbles in terms of quantized charge, and imagine doing the same experiment with electrons and protons, I come to the conclusion that electrical potential should be absolute and indeed have an upper and lower limit.
Is there a flaw with my thinking?