AFT was often an upgrade you paid for.
When you work on a set both the AFT & any auto color switches should be off.
Tuners have AFT off switches to turn it off for a second at channel change.
Those are on the side or rear of the TNR assy. Also some had a switch up
front of TNR to defeat it when fine tuning is engaged. Generally you can
defeat the AFT by grounding the TNR aft pin.
Keep in mind both the AFT AND auto color may have AFT on/off on them.
When done you can put the AFT back on, it does work good.
Chroma Tone was Maggys auto color scheme. In the day we called it the
" brownilator". When on it gives an overall puky brown cast to the pix.
Leave it off for best pix.
73 Zeno
LFOD !