Just look over each option. Next to the size option, you can see the font color option.
You can test the options by editting a single post. That way you won't produce spam.
3 neat tricks off the top of my head...
When using the YouTube tag option, post the YouTube link in the middle and delete all that comes before
the 'v=', including the 'v=' itself.
And when using the URL tag option, you can place an equal sign and a link within the first tag, then type in the middle, so that text brings you to the link. Like so
You can click the QUOTE option on the top right of posts, to see what was typed to create the desired text. Example, you can click the QUOTE button for this post and see how I placed the Google link using the URL tags.