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.
Actually add some useful content here
Newer versions of columns_ui include two versions of the playlist view: a legacy version (Columns Playlist) and a newer version that supports embedded artwork (NG Playlist).
To experiment with the following examples, install the legacy playlist view, Columns Playlist. Also locate the Globals tab in the Playlist view preferences panel and place a checkmark next to “Enable legacy support for globals”.
Experimenting with the legacy playlist view affords you the opportunity to get your feet wet with the TAGZ language. You can switch to NG Playlist once you become more comfortable with TAGZ. Scripts are readily transferable to the new interface, although some built-in variable names are changed.
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; for more information see the articles below:
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.
To create alternating colours for groups of three songs (three red, three blue), use the following code:
Replace 0000dd and dd0000 with your preferred colours. The number '2' in '%_playlist_number%,2' above may be replaced with a different value (say, 5) to align the desired colour with your first list item.
For those using the newer NG Playlist interface, the above code looks something like this:
The _display_index variable could be replaced with list_index if desired. Notice that list_index does not use a leading underscore. Also notice the offset value was adjusted to 1 because the group title occupies the first line.