The look
Named for watercolour painting, aquarelle lips are translucent and luminous, with the colour concentrated centrally and washing out to nothing well before the edge. There is no outline, no defined lip line, and often a deliberately uneven, organic distribution — like a stain from a popsicle, not a lipstick.
How it differs from a standard blush
A regular lip blush still aims for fairly even coverage and a (soft) sense of the lip's shape. Aquarelle deliberately keeps coverage low and patchy-by-design, uses the brightest, most sheer pigments, and feathers even further past the border. Fewer passes, lighter everything.
Trade-offs
Most natural, least 'done', ages gracefully, quick to do. But it does little for a very pale or very uneven lip, offers no border definition for those who want it, and fades sooner because there is less pigment to begin with.
