Of the Scillas, Scilla sibirica is probably the most common - and admired! There are others outlined below which will also please.
Blue is the predominant colour of the flowers of the Scilla bulbs, but there are also a few whites and a pink worth growing.

Scilla sibirica - Bright blue flowers
All Scillas are spring flowering - March being the start, though sometimes earlier. The image below was taken on March 15th. The flowers are well advanced on this, so safe to assume some initial colour in first week of March.
There is nothing quite like the vivid blue flowers of Scilla sibirica, even though sometimes you will have to go hunting for it - being just a few inches tall - 4-6in in a good season!
The Scillas generally, are well suited to being naturalised in drifts below trees, in woodland or even in grass - providing you do not rush about with the lawnmower until all of the foliage had died off.
Scillas are a great choice for following on from the snowdrops naturalised in such positions - and sometimes, it is possible to have the later snowdrops and earlier Scillas at the same time. I have yet to see that, but I am sure that it is possible, for I have photographed both on the same day - although in different parts of the garden.
All Scilla bulbs are available as dormant bulbs in early Autumn and should be planted as soon as possible. They are also available as pots of flowering plants - the nurseryman well aware of how valuable they are at an otherwise dreary time of year - for weather and cashflow!
Scillas are the same family as Hyacinths - Hyacinthaceae - and the individual flowers are akin to the florets on the Hyacinth spikes.