In customizing your blog template, you may find that you want to change the colors supplied by your blog provider. Color codes for HTML come in six digit codes made of numbers and letters. You may see it called "hexidecimal" - that is because they use the numbers 0-9, plus the letters A-F (giving you 16 possibilities) to create the "number" of the code.
The following are some of the sites I use to find the codes for the colors I desire:
http://html-color-codes.com/ This site contains 216 browser safe color codes on one small grid(**more on safe colors in a bit), along with the colors they represent
http://www.computerhope.com/htmcolor.htm Contains codes for the major colors and a separate chart of additional colors/codes to scroll through.
http://www.december.com/html/spec/color.html The hub for links to several pages of different color codes, arranged by hue (not all of which are "safe"):
The neutrals: http://www.december.com/html/spec/color0.html
The warms: http://www.december.com/html/spec/color1.html
The greens: http://www.december.com/html/spec/color2.html
The blues: http://www.december.com/html/spec/color3.html
The purples: http://www.december.com/html/spec/color4.html
And if that isn't enough there are even a large number of codes for the "nameless colors" here: http://www.december.com/html/spec/colorhues.html
http://www.siteprocentral.com/html_color_code.html This site contains a handy little tool for creating your own color. Adjust the red, green, and blue sliders to chose your color, then on the right you can use a pull down menu to find colors that match your color - complimentary colors, analogic, monocromatic, etc. Great when you want to totally redo a blog's "look" but aren't good at knowing "what goes with what" (like me).
**A "safe" color code is a code that is one of the 216 colors chosen as a web standard supported by all computers with color monitors. Today most new computer screens support more than the 256 colors that computer screens of old used, so needing a "safe color" is not as important.