He explains in the post that it goes in postbit legacy template. Just do a search to find the correct place to put the code. :D

thanx for reply, i put the code postbit_legacy , but nothing happen !!
plz after put the code , what we do ?? sorry i am new

I am having the same exact problem. I installed it as he said, as best I understood since I do not speak spanish.

I went to my UserCP and changed my settings for a new font and size and I see no results when I post a new post.

It is hard to understand exactly what this is supposed to do as it is in spanish. If this is supposed to change your default font, size and color in your posts, should we not be editing templates for the blog and cms as well?

Is there any answer to my problem?

"replace it with this"

Is there any answer to my question?

This works on 4.2.3 but it changes every post I have ever made on our forum. For example I go and change font color from black to red. Now every post of mine has now changed to red.

Is it possible to just have the change (font color, size) made to new posts?

Or does anyone know of another mod that would work where the changes would just work with new posts you make?

If you change your template, or add CSS, then it will affect all posts...in order to only affect new posts you would have to use a plugin to check the dateline of posts and only have code added if the dateline is greater than some value you specify.