colour-codinginductorradiotransformertuner
Is there any standard color code available for IF transformers?
Generally in most of the Japanese radio receivers I see red color slug for MW oscillator, white and yellow slugs in AM IF stage, orange color slug for FM oscillator, blue, purple and pink colored slugs in FM IF stage, etc.
Personally, I would use a "cold" color for the negative such as blue or maybe purple.
One "standard" I can think of that's not incompatible with red=positive and black=0V is the standard PC power supply color code:
For more info on wiring colour codes see this wikipedia article.
I am guessing that the listed impedances are actually resistances,
No, they are the impedances of the circuit they are used in. The DC coil resistances will be much lower (as they should be for low loss).
A transformer 'reflects' the circuit impedance on one side to the other, transformed by the turns ratio squared. So if a source with impedance of 60KΩ was connected to the primary side of a 10:1 transformer, it would appear as 600Ω (102 = 100 times less) on the secondary side.
The IF transformers in your table are typically used in AM broadcast receivers that use one bipolar transistor per stage. Each stage has different input and output impedances, which the transformers are designed to match. Here is an example:-
Note the center tap on the primary side of each IFT (which improves Q by reducing loading on the tuned circuit). To determine the primary to secondary turns ratio and resulting impedance transformation, we must decide which primary coil the input will be connected to. For example, using coil 1-2 of the 1st (yellow) IFT we get a turns ratio of 70:7 = 10:1, which would transform 60kΩ to 600Ω (or 30KΩ to 300Ω, or...).
Best Answer
There's no standard that I've found, unfortunately. But, there are some common conventions.
This page has more detailed information than most pages I've found on the subject: https://www.electronics-tutorials.com/filters/if-amplifier-transformers.htm
It includes turns ratios, impedances, intended application, core color, etc., for a small sample of IF transformers. The general advice on that page is to consult the datasheet for the part number, if you can find it. Of course, most of the time there is no part number to be found.
An LCR meter can help identify the winding inductances in a transformer.