We introduce a novel type of self-bound droplet which carries an emergent
color charge. We consider a system of particles hopping on a lattice and
interacting via a commensurately sign-changing potential which is attractive at
a short range. The droplet formation is heralded by spontaneous crystallization
into topologically distinct domains. This endows each droplet with an emergent
color charge governing their mutual interactions: attractive for equal colors
and repulsive otherwise. The number of allowed colors is fixed only by the
discrete spatial symmetries of the sign-changing part of the interaction
potential. With increasing interaction range, the droplets become progressively
more mobile, with their color charge still being energetically protected,
allowing for nontrivial viscous dynamics of the interacting droplet plasmas
formed during cooling. Sign-changing potentials with a short-range attraction
appear quite naturally for light-mediated interactions and we concretely
propose a realization in state-of-the-art experiments with cold atoms in a
multimode optical cavity.Comment: version similar to published, including supplementary material
