I think lilac pollen is... "lilac" blue ( maybe that's mauve), and the pellets
from a pollen trap taste like a lilac blossom.
 
Season report: here in northern B.C. just east of the rockies, we  had a cooler
than average "late winter" and bees were kept indoors an extra week or two from
the Apr 1 target. Now in early summer, it was a very warm 18 deg C yesterday,
the bees are hauling in willow pollen and nectar, and there have been dandelion
bloom sightings in sunny sheltered spots. Winter losses are a bit higher than
normal, perhaps from the abrupt change to cold weather last fall, catching some
colonies not well enough fed.