|Messier 52, in Cassiopeia.|
I had to cheat a bit more than usual to get this picture, because it doesn't actually have any red data. All we needed for our project was blue and green data, so I simply duplicated the green data and used it as red to get this picture. I think it came out all right, according to the data we got most of the stars are fairly neutral or white anyway, so the missing red data wasn't really that important for this cluster.
If you're wondering about the ratio of the picture, it's actually two different fields that I combined which we took in order to ensure we got the entire cluster.