You may never see the light of day if you try and read the entire Columns UI thread, so this most of the useful information for new users will slowly be filled in here.

Rather than blindly using someone elses config, it is best to get a grasp of the titleformatting language, so you can create personalised configs yourself. The language used in titleformatting is tagz; an overview of it is available in the titleformat_help.html file in your foobar2000 directory. Several useful function were also added after that document was last updated. These include:

• $codec()
  Returns codec tech info field if available, or file extension otherwise
• $tracknumber([x])
  Returns tracknumber if available, zero paddded to x digits.
• $channels()
  Returns a number of channels, word description if stereo or mono.
• %_filesize%
  Filesize of file in bytes.

Square brackets denote an optional field.

$div(%_filesize%,1048576).$num($muldiv($mod(%_filesize%,1048576),100,1048576),2) MB

In your colour string, use this code for the colour you wish to alternate:

$ifequal($mod(%_playlist_number%,2),0,<colour a>,<colour b>)

replacing <colour a> and <colour b> with your desired colours.