Stock should be as follows:
Orange - Weekly seasons, normal single/return tickets. rovers/rangers, some receipts, meal vouchers, reservations, berths.
Grey - Any season over one week and less than one year.
Blue - (a more robust plastic ticket) - Annual Seasons (other than those in NSE area).
Gold Card - Annual seasons in NSE area.
There are then other ticket stocks as follows:
1) 1 day bus pass (London area) -red/white
2) Travelcard (Day) - red/pink/white
3) Travelcard (period) - red/pink/white (most stations will issue these on normal orange stock)
4) Regional PTE tickets (centro, metro etc)
You've also still got RSP4407/RSP4408 'paper' tickets.