Ostara is the spring festival.
This event is celebrated on the 21st of March at the moment that the day and night are equally long, after the winter has been. The days are now longer than the nights.
It symbolizes the end of the dark times, and we celebrate that the light is slowly but surely winning.
Everywhere you see it: plants come into bloom, lambs are born, the birds come back.
This occasion is celebrated with colored eggs, because eggs are a symbol of new life, what spring also means: new life in nature.
The color red is the color of life, which is why eggs are painted red, for example. Green stands for the new plants that spring up, and yellow for the sun.
In ancient times, eggs were buried around the field to promote the fertility of the land.
This is where the tradition of hiding eggs comes from.
The hare seems to come from the legend of the Goddess Eostre, goddess of the rising day and spring (bastard of Astarte, the fertility goddess).
Originally it was a chicken, which had the annoying habit of hiding the eggs. When punishment changed the Goddess the chicken in a hare, which she had to go looking for again.
If the legend really exists, I do not know.
There are also often fires lit at this occasion.
This was and is being done to spread the light of the newborn sun over the land.
We celebrate life, and that is certainly the case at this event.
The origin of Ostara
There is no question that the Germanic tribes paid tribute to a deity at the spring equinox.
Our Easter customs undoubtedly have pagan roots and are even older than the Christianization of the West. The first written mention of the "goddess Eostrae" comes from a work by the English church historian Beda Venerabilis, a monk of the 8th century.
This indicates that the name of the Easter month was due to just that goddess.