M31, the Great Nebula in Andromeda, is the nearest major galaxy to our own. It has roughly twice as many stars as the Milky Way, but a similar structure and appearance (if we could see the Milky Way from outside). You can see how brighter, bluer stars are concentrated around the outside of the galaxy, while those in the centre are cooler and hence redder/yellower.
It is possible to observe and photograph globular clusters of stars that form a halo around M31, just as similar clusters surround our galaxy. Around twenty such clusters are visible in the image below. Two smaller galaxies, M110 (top centre) and M32 (below M31, to the left of the bright star) are visible in the image below.