Description of problem:
systemd prints raw escape codes if custom options are set in the $LESS environment variable.

For example, use the -F option to auto-quit if the output fits in the terminal:

$ export LESS="-F"
$ systemd-delta
ESC[1;32m[EQUIVALENT]ESC[0m /etc/systemd/system/default.target → /usr/lib/systemd/system/default.target

1 overridden configuration files found.

Personally, I have in my ~/.bashrc 
  export LESS="-FiX"

If I unset the $LESS environment variable, then I get green text for "[EQUIVALENT]"

$ unset LESS
$ systemd-delta
[EQUIVALENT] /etc/systemd/system/default.target → /usr/lib/systemd/system/defaul
^^^^^^^^^^^^
   green

I see this with other systemd commands also, e.g., systemctl list-units tries to print "failed" in red letters, but I get this:

systemd-...-clean.service loaded ESC[1;31mfailed failed   ESC[0m     Cleanup of Temporary Directories
systemd-...-setup.service loaded ESC[1;31mfailed failed   ESC[0m     Recreate Volatile Files and Directories

Side-note: those units failed because of bug 857708


Version-Release number of selected component (if applicable):
systemd-44-20.fc17.x86_64
less-444-5.fc17.x86_64

How reproducible:
every time

Steps to Reproduce:
1. set your favorite options in the $LESS environment variable
   export LESS="-F"
2. systemd-delta
3. systemctl list-units
  
Actual results:
Ugly raw escape codes like ESC[1;31m are printed

Expected results:
Red or green text, or plain uncolored text if colors not possible

Additional info: