Bob,
In Unix everything is a file... regular files, links, directories as well as the block and character special devices. These entities you are seeing have a specific purpose to keep the Unix Operating system functioning.
Now, the /bin/ls binary has functionality that allows colorization based upon file type, and other factors. Yes, like you, I typically work in listings that are black and white for ease of viewing.
The block device for /dev/sdb is used by a driver in the kernel to access that disk drive. /dev/sdb1, for example, would be the first partition on that disk drive, etc...
Why are you worried about these?
From: "Bob Goodwin ~ Zuni, Virginia, USA" <bobgoodwin@wildblue.net>
To: users@lists.fedoraproject.org
Sent: Monday, September 23, 2013 4:58 PM
Subject: Re: permissions -