The color coding helps you visually identify the controlling put/call/neutral activity. 1st level coloration: Green represents call activity being dominant in that ticker/sector/group (P/C ratio = 0-1.0). Yellow activity represents neutral activity in the ticker/sector/group (P/C ratio = 1.01-1.50). Red activity represents bearish activity in the ticker/sector (P/C ratio = 1.51-3.50). Maroon coloration represents extremely bearish activity (P/C ratio > 3.5+). On 2nd level data, green represents strikes and options that are call volume dominant and red represents strikes and options that are put volume dominant.