[Sprint Samsung Galaxy S III] fergie716:
First you need to set up apktool on your computer/laptop. Google "How to Set Up Apktool". I don't know what OS your home computer/laptop so you'll have to tailor your set up.

I use Windows, here is a decent guide for Windows 7 x64

After you install the prerequisites (java, sdk etc) go here and grab the modified apktool.jar AND aapt.exe and place them in your apktool directory (it will replace the older ones you used in the guide, the one I linked to is a new, updated version that works with TW and AOSP very well)

After you have everything installed and apktool is ready to go, pull these files from your ROM and place them into your apktool folder (you can use adb pull or simple copy/paste the apk's from your system onto your SD then transfer them to your computer). You will need:

-/system/framework/framework-res.apk
-/system/framework/twframework-res.apk
-/system/app/SecMms.apk
-/system/app/SystemUI.apk

Place all of these apk's into your apktool directory. Now open a new command prompt window and "cd" your apktool folder. For instance, mine is C:\apktool\ so I type

cd apktool

Next, type

apktool if framework-res.apk
apktool if twframework-res.apk

This will install resources so you can now decompile apk's that use framework-res.apk and twframework-res.apk resources

Next you can decompile all of those apk's. SecMms.apk is the messaging app, SystemUI.apk is the statusbar and the two framework files are the system framework

To decompile:

apktool d framework-res.apk

After you make changes you recompile (your new apk will be in the framework-res/dist folder):

apktool b framework-res

You can alter the folder names of each of these. For example if you want the decompiled framework-res folder labeled per ROM you could do

apktool d framework-res.apk framework-res-blazer

So, to make everything red and black your going to have to manipulate both xml's and png's. For png's I suggest Paint.NET or GIMP, both are free. I honestly prefer Photoshop and have been using it for quite some time, however it is expensive (I think they do a free trial and have discounts for students). Pay special attention on ".9.png's", these are stretchable images and need to be treated differently (Google some guides on that)

For XML's. in framework-res/res/values/ you will find plenty of colors to change, especially for TW. I would go to colors.xml and change the holo_blue_light and holo_blue_dark to a red color (I use this tool to find appropriate hex colors that android uses). If you see an "ff" in front of the color it just means that the color will be shown 100% (no transparency).

So I would dig through those apk's, the easiest parts will be modifying the images as sometimes colors can be tricky to mod in xml's, but like I said, those two holo colors do control a lot. Same in the SecMms.apk and twframework-res

After you recompiled you apk's you need to copy over the META-INF folder AND the AndroidManifest.xml from the original apk to your new one ( I use WinRar, however 7-Zip is free)

Here is a guide I made on how to make a flashable zip after you made your apk's, just follow that and make a backup before flashing

Good Luck!