i think the 6 theme has separator
you can put separators on any theme by paste this to rtconfig (making backup first)
tcp's
mcp-----snip---
Layout "Separator" "separator"
clear tcp.*
set tcp.size [400 10 10 1]
Endlayout
-----snip----
-----snip----
Layout "Separator" "separatormcp"
clear mcp*
set mcp.size [10 319]
set mcp.extmixer.mode [1]
set mcp.extmixer.position [0]
Endlayout
-----snip----