let members set default text formatting for posts through their options

[Oracle simsim]

Hello every programmer

I want to let my members choose their default font family, size and color for their posts. so They don't have to set them each time when they write a post.

Many members prefer to write in specific color , font and size Also they post a lot. It will be really nice and helpful if I help them by letting them to choose their default formatting for next posts through their General Settings page or whatever page.

It is not difficult to create a form with drop-down menu in a custom page (e.g misc.php?do=post_format) then process that form on submit and save the values in user fields or another table. This is not really a problem. The problem is how to let those values affect the their posts.

We can do that, in postbit write something like this

<span style="font-family: {var}; color:{var}; font-size:{var}">{vb:raw message}</span>

but This is not really a professorial work for several reasons

1- if the member change the formatting setting later. all the old posts change too.
2- the formatting will not appear during the posting process (i.e in the WYSIWYG)

I want the formatting values to be hardcoded in each posts. so they will not change later and they will be visible during writing.

How do I change the CKEditor setting dynamically? so it start with settings specific to each member (or specific in general)? is there a simple way to do that ? I am good in javascript, PHP , HTML, CSS But I can't figure out how to do that?

Help please. surely this will help others too