Roman Numeral iiii or iv

There are two forms for the Roman Number 4; it can be IV or III.  Most clocks use IIII for the 4th hour.  Also IIII can be found on the Roman Colosseum.  Note that the Roman Numeral quad-I maritime flag is composed of four colours.  Likewise there are already established four coloured maritime flags like Zulu and #9.  NATO's maritime flags for 'Division' and 'Squadron' also use four colours but of the same palette.   The IIII flag however, maintains its own palette.

Most but not all Roman Numeral clocks employ the IIII for the 4th hour.  You can see to the left a clock with IIII instead of IV.  One major exception is Big Ben's Clock Tower in London, that uses the official IV for the 4th hour time slot.