Abstract
It has long been textbook 'knowledge' that quarks and gluons exist exclusively inside of hadrons and glueballs because of colour confinement. However the $SU(N)$ group contains $N-1$ Abelian generators. We argue that since the Abelian components of the gluon field can be meaningfully isolated by the Cho-Faddeev-Niemi-Shabanov decomposition, the corresponding gluon excitations are physical entities of neutral colour charge that can propagate freely. Their mass can be estimated on dimensional grounds and is similar to the pion mass.