We don't have synonyms for colorguard yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are color guard and colour guard.
(n) :
Alternative form of color guard [(military, scouting) A uniformed group, especially of soldiers, police officers, Scouts, or school representatives, who present their institution's flag (and sometimes other flags) on ceremonial occasions.]
(n) :
Alternative form of color guard [(military, scouting) A uniformed group, especially of soldiers, police officers, Scouts, or school representatives, who present their institution's flag (and sometimes other flags) on ceremonial occasions.]