Script buffers.pl has been improved. Now you can hide categories, and there's color for lines according to hotlist (activity on buffers). There's new config options, you can set with /set command:

Hide categories:

• /set plugins.var.perl.buffers.show_category off

Change colors (replace "color" by your color, which may be "fg" or "fg,bg"):

• /set plugins.var.perl.buffers.color_number color
• /set plugins.var.perl.buffers.color_slash color
• /set plugins.var.perl.buffers.color_hotlist_low color
• /set plugins.var.perl.buffers.color_hotlist_message color
• /set plugins.var.perl.buffers.color_hotlist_private color
• /set plugins.var.perl.buffers.color_hotlist_highlight color

A screenshot is better than long speech:

Updated on 2017-05-13: the script is now obsolete, replaced by the builtin buflist plugin, introduced in version 1.8.