Here is a manual for that model of American Standard WH......
LINKNOT real informative..but does have some info that could be of use to you.
As for that flame........
I know you stated you cleaned everything......including the main gas orifice?
It is screwed into gas valve right where that air shutter is.
Need to remove the orifice and clean it using alcohol and air....don't be poking anything thru it :B
The air shutter......
Flame should be mostly blue with tinges of yellow/orange tips
Open air shutter to feed more air into burner tube.
Orange flame is due to being fuel rich (air starved)
You should also check the propane pressure your LP regulator is providing. (Low propane pressure will result in mre flame pattern)
You need a manometer to test.
Hooked up to the test port at gas valve
Turn on at least 50% of propane appliances.......pressure should be 11" WC with water heater in service.
Manometer....
Fill tube with water to 'zero'
11" WC.......water column moves to 5 1/2" each side
If low....need to adjust Propane regulator
