  Three-dimensional colored gravity refers to nonabelian isospin extension of
Einstein gravity. We investigate the asymptotic symmetry algebra of the
$SU(N)$-colored gravity in (2+1)-dimensional anti-de Sitter spacetime.
Formulated by the Chern-Simons theory with $SU(N,N)\times SU(N,N)$ gauge group,
the theory contains graviton, $SU(N)$ Chern-Simons gauge fields and massless
spin-two multiplets in the $SU(N)$ adjoint representation, thus extending
diffeomorphism to colored, nonabelian counterpart. We identify the asymptotic
symmetry as Poisson algebra of generators associated with the residual global
symmetries of the nonabelian diffeomorphism set by appropriately chosen
boundary conditions. The resulting asymptotic symmetry algebra is a nonlinear
extension of Virasoro algeba and $\widehat{\mathfrak{su}(N)}$ Kac-Moody
algebra, supplemented by additional generators corresponding to the massless
spin-two adjoint matter fields.
