Red, Yellow, Green Status with Range Values

HardWork

How do you work with a range value and RYG status balls? For instance, I have a temperature range of 68 to 79. I would like for the RYG to associate as follows:

Red: </= 67 and >/= 80

Green: 70 through 77

Yellow: 68 through 69 and 78 through 79

I just can't figure out how to link the ranges correctly.

HardWork

This is what I have tried so far:

=IF([CT TEMPERATURE]@row, </=67, "Red", IF([CT TEMPERATURE]@row, >/=80, "Red", IF([CT TEMPERATURE]@row, 70-77, "Green", IF([CT TEMPERATURE]@row, 68-69, "Yellow", IF([CT TEMPERATURE]@row, 78-79, "Yellow")))))

but I get the #UNPARSEABLE of death message.