Modify Inline Styling, Multi-Elements Deep

I'm attempting to modify the coloring of a CometChat on a website which will remain anonymous due to having a non-modified CometChat. I just want to change the coloring, but prefer to use Greasemonkey over a User Styling extension due to not wanting to install a single extension for a single page.

I've changed the background color so that it is black, which is fine until I go to modify the default text color (Black), to be white.
The system appears to style text based on the color in a Cookie, but it uses an Inline Style on a span.

I can't figure out how to modify only the Inline Style where it is "color:#000000" (No, they don't have an appending ";") without changing all other colors, and removing a feature from the chat.

I tried:

Using jQuery's .attr to find the value, then apply a class which has an !important color.
Using .attr to change the color directly.

I Also tried span[style="color:#000000"] and a few other methods, nothing has worked so far.

One thing I noticed is that while trying to alert() to see if it's working at all (In some attempts during .each), it wouldn't create the alert. The only reason that I can think of is that it is several Div's deep into the document. (html > body > div#container > div#currentroom > div#currentroom_left > div#currentroom_convo > div#currentroom_convotext > div > div.cometchat_chatboxmessage > span.cometchat_chatboxmessagecontent > span (The one I wish to Edit) )

Solution

I'm guessing that that/those span(s) is/are added by AJAX (Can't tell from the question). Whether they are or not, you can use waitForKeyElements() to change it/them:

// ==UserScript==
// @name     YOUR_SCRIPT_NAME
// @include  http://YOUR_SERVER.COM/YOUR_PATH/*
// @require  http://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js
// @require  https://gist.github.com/raw/2625891/waitForKeyElements.js
// @grant    GM_addStyle
// ==/UserScript==
/*- The @grant directive is needed to work around a design change
    introduced in GM 1.0.   It restores the sandbox.
*/

waitForKeyElements (
    "#currentroom_convotext div.cometchat_chatboxmessage > span.cometchat_chatboxmessagecontent > span", 
    changeChatMessageCSS
);

function changeChatMessageCSS (jNode) {
    jNode.css ("color", "white");
}

Indicate whether the page resets the inline styles or uses !important in its CSS. (It probably does not do either.)