Text Box Tool Default Font Color

You may change the appearance of the Text Box itself (not includes text color) by doing the following steps:
1. Show the "Comment & Markup" toolbar in Acrobat 8;
2. Place the mouse pointer onto the "Text Box Tool" and do a right-click;
3. By selecting the "Tool Default Properties" from the bottom of the list, you may change the default color and more.

Or: (this will keep the appearance AND text attributes as default)
1. View > Toolbars > Properties Bar;
2. You may change the appearance of the current Commenting Tool; plus change the text attributes while you are inputing the comments;
3. When finished the commenting, put the mouse pointer onto that piece of comment (you may also point to any comment which you wish to set as it's default);
4. Right-click, then select "Make Current Properties Default"

Have Fun!

A simple solution is to cut and paste text from another program like MS Word. I use Acrobat 9.0 Pro and it works great. I change the font color, font style, and size and Acrobat seems to accept those properties when it is pasted into the box. This does not seem to work with the typewriter tool however.