They are python based. /usr/bin/landscape-sysinfo opens up a python library:
from landscape.sysinfo.deployment import run
Which is located under:
/usr/lib/python2.7/dist-packages/landscape/sysinfo
But, you will probably have a difficult time "just adding color" here as the package will be updated from time to time wiping out your changes. But feel free to mess around with it. :)
Note this package is completely open source and housed in the landscape-client source code. It's installed with the 'landscape-common' package onto your system.
If you just want to modify the message you see printed out, there are a lot of ways to do that, and these are great starting points: