Easter is 'date mobile' festivity: its date varies year to year
because it correlate with the lunar cycle.
Jewish Passover and Christian Easter celebrate different event
and never can fall on the same day.
Within Christianity then there are two different rules depending
on whether the Gregorian calendar (Catholics and Protestants)
or the Julian calendar (Orthodox) are used.
In the Orthodox and Eastern Catholic Churches,
Easter eggs are dyed red to represent the blood of Christ,
with further symbolism being found in the hard shell of the
egg symbolizing the sealed Tomb of Christ,
The cracking of which symbolized his resurrection from the dead.