A number of cultivars of box elder are noted for having distinctly colored late winter shoots - these are typically described as having a blue or purple cast with a white "bloom". These are not to be confused with seasoned growth on 'Winter Lightning', which will be a bright golden, yellow. The very light colored shoot growth is reputedly what gives this cultivar its name - they resemble the electric whitish, silvery blue of lightning bolts.

It's a bit early to be noticing them now - I'd look for more coloration in February or March.