the old ta 2000 is wired like this
w2-black O-pink X-blue R-red Y-yellow G-green E-brown
according to http://www.mobilehomerepair.com/media/img/coleman/119005.pdf
y is 1st stage
w2 is second stage
g is fan
r is switched side class2 power single source
x is inswitched (common)
O is damper cool
E is emergency heat relay

So where do they go on the RTH3100C?