Honeywell TH8320 not compatible with 3rd gen nest

[Lovnit67]

I have a Honeywell TH8320 and would like to install my 3rd gen nest. When I go through the setup process it says my wiring is not compatible. Can someone verify this please and give me instructions on how to wire if it is compatible. 
Wiring 

[Patrick_Caezza · Accepted solution]

@Lovnit67 

Your current thermostat is compatible.

Give this a try

Gray - Y2 to Y2

Blue - E to * (set as emergency heat)

Pink - S1 not used, tape off

Brown - S2 Not use, tape off

Red - R to Rc (jumper to RC not needed)

Orange - O/B to O/B

Yellow - Y to Y1

Green - G to G

Black - C to C

[Lovnit67]

Thank You very much  @Patrick_Caezza !!!!

Because I'm a curious person, why are pink and brown not needed on the Nest but are on the Honeywell?

[Patrick_Caezza]

@Lovnit67 

Those two wires are for external sensors that the Nest doesn't support.