For 6 to 9 wt. Yellow For 7 to 11 wt. Green For 8 to 12 wt. Orange For 9 to 13 wt. Red For 10 to 14 wt.
Heads are inexpensive, cast further, sink faster, and allow the quick changing of line densities.
The rule of thumb is to order one size larger shooting head than your rod's line designation.