Here is my proposal for a Tails logo:
https://mega.co.nz/#F!Z4hhlRKL!fp5UKraTi_kzzF3S9CBd6w
Suggestions and criticism are welcome!
I've included a color version for the web, and a black and white version
that I think would work well for the boot splash screen. For the color
version I've stuck with the green and purple, although that could
certainly be changed.
The text is FreeSans (GPLv3+), tweaked a little in inkscape. I'm not
particularly attached to it, other ideas would be welcome.
Tom