Quite a change colour-wise, little change function wise (only a bit to randomly change active tag colour).
Obligatory screenshot:

Screenshot of awesome

This is what I added:
Added focus_choices to the bg table

 bg = {normal = "#e7e7e7", focus = "#d97600", focus_choices = {"#669bcb", "#d97600", "#6eb22c"}, urgent = "#ffaa88"}

Changed taglist.label

 function taglist.label(t)
                local bg_color
                local fg_color
                local background = ''
                if t.selected then
                        local choice = math.random(1,3)
                        bg_color = bg['focus_choices'][choice]
                        fg_color = fg['focus']
                end
...function continues

As always, the latest version of my config can be found here.