Lilacs are a symbol of the emotions of early love.
The color lilac used to be associated with mourning. Black was worn or used to symbolize a recent death in some European and North American cultures. But after a year of mourning, key mourners, such as the widow, could switch to lilac for clothing, the border on stationary, etc. This is mostly an older use, such as in the late 1800s.
Like other variations of purple, lilac is also associated with spirituality.
Syringa vulgaris (Lilac) is the state flower of New Hampshire, because it "is symbolic of that hardy character of the men and women of the Granite State" .
May is lilac here in New England,
May is a thrush singing “Sun up!” on a tip-top ash tree,
Color of lilac.
Heart-leaves of lilac all over New England,
Roots of lilac under all the soil of New England,
Lilac in me because I am New England,
Because my roots are in it,