Galaxy morphology catalog

In other words, there does not appear to be a dichotomy between blue and red galaxies. Both the colors and the morphologies of galaxies are found to correlate strongly with their environments.

Red and early-type Shapley-Ames galaxies are dominant in clusters, whereas blue late-type star-forming objects dominate the general field. Interestingly, the colors and morphologies of galaxies in small groups resemble the field and differ from those in clusters. As noted by Baade, the presence of dust and star formation are very closely correlated, except in a few galaxies that probably had unusual evolutionary histories.