I altered my background, text, link colors...how do I alter the green highlighting for active players?

Check out renderlot.html. There's a line that says something like

if player is participating, add style="background-color: #00FF00"

Thanks! That worked.

I also added that statement (in my case highlights gray on black background):

"{%if player.key.id() in container.lot.playersParticipating %} style="background-color: #A4A4A4" {%endif%}"

to the rank and win/loss columns as well, so it highlights all three columns for people participating in ladder.