Black lockout screen after rooting & deleting dtcp_apk.apk topic

Hey folks,

after rooting I deleted the dtcp_apk.apk, following a tutorial on the web to get rid of the Amazon ads.
Worked fine, ads are gone.

But now the lockout-screen is just plain black, except the first lockout screen after starting the Kindle.
It's not like thats a big thing, but i would like to have colored lockout screens.

Any ideas how to get them?

Thanks!