If you change your background from light to dark, make sure to change any text that is on that background from dark to light. If you don't, your blog will be hard for people to read. If your blog is hard for people to read, people will stop reading it...
You should be careful to not put your blog template live until it is fully ready, as you don't want to turn off possible visitors.
Every item of text has an area where you can change the color, just browse through the Palette file. There are also some earlier posts in this blog that explain how to locate and change font colors.
In general, use light text on dark backgrounds, and dark text on light backgrounds. Try subtle changes first -- if the default blog is light colored and you like blue, try using a light blue first to get your feet wet.
Also, don't forget that not everyone has the same tastes as you... so while a blog is a way to express yourself, if your goal is to reach as many people as possible, you have to compromise sometimes.
Here are some examples of proper light/dark balance (assuming these members have not changed their blogs since):
http://laurelcrowned.blogstream.com/http://goneforever.blogstream.com/http://dearmrpresident.blogstream.com/http://shortales.blogstream.com/
