I did a science lab about chromatography paper and the black ink did not have a variety of colors when seperated. Is the black ink a heterogenous...

Black ink is a homogenous mixture because it is a solution and all of its components are in a single phase.  

A mixture is a combination of two or more substances in which each substance retains its identity. In other words, the substances that make up a mixture do not chemically react to form new products.

Mixtures can be either homogenous or heterogeneous. A homogenous mixture has a uniform composition and uniform properties throughout. The substances within a homogenous mixture are in one phase. All solutions are homogenous mixtures. On the other hand, a heterogeneous mixture does not display a uniform composition throughout. Trail mix and salad are two examples of heterogeneous mixtures. Each bite or handful of trail mix or salad is different.