Alright, so bear with me here, as I'm not much for making good guides, but I'll try my best. Firstly, you'll need this image here (right click and save it):
Then, take the Gmail APK out of your system/app folder from your phone. There's many ways to do this, if you're familiar with adb, you can use that, or you can use
Android Commander, or Root Explorer. You just need to take the GMail APK out somehow. Make two copies of it somewhere on your desktop, so that you have a backup, and then delete the original apk from system/app. Don't panic, if anything goes wrong, you have your backup (although this is ridiculously simple to do)
Now that the Gmail APK is on your desktop, open it up using 7Zip or WinRAR. Either one will work. You don't need to change the extension, both 7Zip and WinRAR handle apk archives just fine.
Using either of those programs, navigate to "\res\drawable-mdpi-v9\". The file you're looking for is called "stat_notify_email.png". Delete that file, and then drag and drop the above one in there. The image I linked you to in the first part is named properly already.
Put the apk (making sure you never changed the file extension) back into system/app, and then restart your phone. Send yourself a test email to check, and if you did it right, it'll be just fine
. Unfortunately, I don't know why this icon is included (perhaps Gingerbread?) but you'll have to do this with each GMail Update
.
And yes, in case you're wondering, you've just learned the beginnings of theming your own APKs
Again, this guide might not be as clear as I want it to, and veteran users might even point out that its inefficient and that there's a better way; no matter what, I know that this works
Feedback is welcome.