Yosemite Login Window Rebranding

[Jason]

I was reading a thread about this today here:
http://www.tekrevue.com/tip/custom-login-screen-wallpaper-os-x-yosemite/

I've been looking for the correct way to change the login window background to a corporate branded one. I was able to do so with some success by following the process above where i replace /Library/Caches/com.apple.desktop.admin.png with my own image.

It does display that image, but it appears as if through a filter. The colors look less saturated and there was some light text on my dark background which I no longer see. A user commented that apple adjusts the brightness and contrast.

Does anyone have a more effective process for this so that the image is not altered?

I've also seen this:
http://jacobsalmela.com/os-x-mavericks-change-login-window-logo-wallpaper/

But Deeper doesn't seem to fix the issue either.

[nessts]

Seems to me that Apple got offended by us wanting to make our computers not be the way Apple thinks they should be and they change that every single release since 10.6.8. I spent hours trying to get it right on 10.7 and then it changed again on 10.8, at that point I stopped caring from a time/value perspective since Apple seems determined to make you want to like their way of doing things. So it has been a couple of years since I looked maybe some of the real smart people who figure everything out have done it for 10.10 though. It would be interesting to see.

[lashomb]

Jacob has an updated post on that for Yosemite. http://jacobsalmela.com/customize-os-x-yosemite-login-screen/

[#4]

I've had success changing the logo image from Apple's to various other things, but since 10.9 it's not worth trying to change the entire background.

As always, feedback.apple.com for such things.