  A complete, straightforward and natural Lagrangian description is given for
the classical non-relativistic dynamics of a particle with colour or internal
symmetry degrees of freedom moving in a background Yang-Mills field. This
provides a new simple Lagrangian formalism for Wong's equations for spinless
particles, and presents also their generalisation, in gauge covariant form, for
spin-$\frack$ particles, within a complete Lagrangian formalism.
