Four Color Fear - The Forgotten Horror Comics of the 1950s is lurid looking volume from Fantagraphics from a few years ago and is a real bargain. It's chock full of vibrantly colored grisly stories from a gaggle of 50's horror comics not from the EC line. These are the other guys, specifically the likes of Avon, Farrel, Fawcett, Harvey, Standard, and such.
These are comics stories by real pros, many who worked for EC too like Wally Wood, Basil Wolverton, Al Williamson, Reed Crandall, and George Evans as well guys like Bob Powell, Howard Nostrand, Jack Katz, Joe Kubert, and Jack Cole among many others. There are forty stories in this thirty dollar collection, a bargain for sure. Here is a detailed listing of the contents thanks to the Grand Comic Book Database.
There is also a pretty extensive cover section as well as a detailed and fascinating set of notes from the editor and collater Greg Sadowski. If you can find a copy, I highly recommend Four Color Fear. Here's a link to the Fantagraphics listing.