[Sony Ericsson Xperia Mini, Mini Pro, Xperia Pro, A] GSUKeitarou:
Well, hello, i hope this wasn't posted before, but i certainly didn't found it here, so i had to test it many times to make sure it worked.

May work on all MDPI devices, but since i only own the wt19i, i can't tell for sure.

Now to the main subject:

Needed Tools:

Rooted Phone

CWM

APK Tool

SystemUI.apk

framework-res.apk

SemcGenericUxpRes.apk

ZIP-Capable archiver

Notepad++ or any good text editor

Brain (is a MUST)

Also you may want to download a couple of CWM-flashable files:

1.- Stock (clean/unmodded) SystemUI.apk, (this in case something goes wrong)

2.- Example SystemUI.apk

Basic Step by Step Setup:

1.- After you've download APKTool, unzip it wherever you like

2.- Copy and paste all 3 apk files on APKTool's folder (see attachments for files)

3.- Shift + Right Click on any empty part of APKTool's folder

4.- Click on "Open Command Window Here"

Once the comand prompt is open, type the following (press enter after typing each line):

apktool if framework-res.apk
apktool if SemcGenericUxpRes.apk
apktool d -f SystemUI.apk

Don't close the command prompt window yet

This will get us the resources and decompile the stock SystemUI,apk, we'll also get a new folder named SystemUI

Step by Step Editing:

1.- Inside SystemUI folder, go to into these subfolders: smali/com/android/systemui/statusbar

2.- Open StatusBar.smali with your text editor (Right click -> choose your editor)

3.- Go to line 388 (or search for the stated code), it must be

const/16 v16, 0x4

4.- Replace it with

const/16 v16, -0x3

This makes transparency possible :)

5.- Save and close the file

6.- Now go back to the SystemUI folder and go into these subfolders: res/values

7.- Open drawables.xml with your text editor

8.- Edit the parameters as you like, here goes the explanation:

(if the image doesn't appear above this line, sorry. Check attachment for explanation)

NOTE: If you're using the SystemUI.apk that comes with QuickPannel and want to make it transparent, you need to do This

Thanks to Jobayer for sharing this info

As for the color codes, they're in hexadecimal format, they go from 00 (0) to FF (255) and they come in pairs:

9.- Save and close your file

Now compile back the SystemUI.apk:

This is kinda complex, but if you're here already, should be a walk in the park

1.- First, we need to use the command prompt from before (you didn't close it, did you?)

2.- Now we'll make the build files by using this line on the command prompt:

apktool b -f SystemUI.apk

(thanks nik2808 for pointing a mistake i made with the code)

3.- Now we go back to the APK Tool folder and rename the SystemUI.apk to SystemUI.zip

4.- Open SystemUI.zip

5.- From the ZIP, copy the META-INF folder and the AndroidManifest.xml file to SystemUI/build/apk subfolder

6.- Repeat step 2, this will get us a signed SystemUI.apk file

You can close the command prompt window now, the signed file will be on SystemUI/dist subfolder

Once you got your customized SystemUI.apk, you can install it by:

1.- using any file explorer, replace the one on your system folder with the new one, change the permission to Read (all) Write (owner only) Execute (none) and reboot your phone

2.- open the demo flashable zip and replace SystemUI.apk with the new one, then flash it with CWM, no need to wipe anything

Man, writting all this was quite long...

BONUS: To get any color you like easily

1.- open Paint (yeah, the windows thingy)

2.- go to Edit Colors

3.- chose any color you like

4.- you'll see "Red Green Blue" values on the lower left, these are the DECIMAL codes for your color

5.- open the Calculator and switch it to Programmer (alt + 3)

6.- make sure DEC is selected on the right pannel

7.- type the DECIMAL value for RED color

8.- press HEXA on the right pannel, this will get you the HEXADECIMAL code for RED in your color

9.- Repeat 6 to 8 for GREEN and BLUE and you'll have your code.

Example: Yellow will be FFFF00

Now you need to decide the opacity from 00 (transparent) to FF (opaque) and use that code on the beginning.

Example: 50% transparent Yellow will be 80FFFF00

Now use that code on the desired spot and voilà :)

Full Transparent code is 00

25% opaque is 40

50% opaque is 80

75% opaque is C0

100% opaque is FF

I hope you guys find this post useful, thanks for reading, and sorry, it's long and my english sucks nowadays...

If you test this on a different phone model and it works, let me know so i can add it to the list of "working in..." list