I've got a free wordpress blog, I'de prefer to understand how to change css or place an element to create Code lines colorful, when utilizing a Programation Language or HTML which.
I believe you're searching for this. Simply place in your "visual" editor, not in HTML editor.
[sourcecode language='html'] Here Goes the code to Higlight [/sourcecode]
Should you host your blog yourself you are able to download a syntax highlighting wordpress plugin within the admin section. If it's located on the platform e.g. wordpress.com you're probably unable to download and install plug ins yourself.