I have followed the steps in here, and the app runs, but I am running into a little problem. The buttons for input and output are nigh invisible, as they use the same grey background color as the entire page, with their text being merely a slightly whiter grey. It's practically unreadable. See here.
I tried to give them an orange color by
color: UbuntuColors.orange in each button definition, but I am still getting the same grey thingy. I must be doing something wrong, but what?
I was able to fix the problem by purging the PPAs using PPA-Purge, and then reinstalling the Ubuntu SDK from the main servers (apparently, it's there for 13.04 without PPAs). Now my buttons are visible, but giving them another color does not work.
ReferenceError: UbuntuColors is not defined. This last one is apparently a bug, https://bugs.launchpad.net/ubuntu-ui-toolkit/+bug/1197293