Blue is one of those colours that genuinely works on almost everyone, and a long sleeve dress in the right shade of blue is one of the most useful things you can own. Not useful in a boring way. Useful in the way that means you actually reach for it repeatedly rather than owning it out of good intentions and wearing it twice. The long sleeve is the detail that makes this category worth paying attention to year round. In summer you get the coverage for air conditioned offices or cooler evenings without sacrificing the dress. In autumn and winter it sits beautifully under a coat and keeps you warm without requiring a separate layer underneath. We have been pulling together our favourite blue dresses in this style across every shade, from pale sky and soft chambray tones to deep navy and rich cobalt. The ones that photograph well, transition between occasions without much effort, and hold their shape after real wear. Blue does not ask for attention the way red does. It earns it quietly, and that is exactly why it lasts.