IB30-16.5 AC Motor Identification
Based on the capacitor values, I would say that the motor is the permanent split capacitor type (PSC). The capacitor is a run capacitor that remains connected at all times. The highest resistance measurement bust be the sum of the main and auxiliary windings. Therefore the black lead must be the common connection between the two windings.

It is difficult to determine which is the main winding and which is the auxiliary winding, but is seems more likely that black and white would be the colors used for power. I found one reference that shows the connection this way:



Additional Thoughts:

It would be useful to carefully examine or measure the winding wire diameter. If there is a difference in diameter between the two windings, the winding with the smaller diameter would be the auxiliary winding.

Motors like this are sometimes constructed with two identical windings so that the direction of rotation can be reversed. One method of reversing a single-phase motor is to reverse the connection of one winding end-to-end. That requires a 4-wire motor. The other method of reversing is to connect the capacitor to the opposite winding.

Wire colors are not very consistently used to signify functions. Where they are used, their significance varies from one country to another and from one manufacturer to another. Manufacturers ship motors all over the world for use by other manufacturers. They may youse their own color codes or those requested by their customers.

For products that they encounter locally, repair professionals may become familiar with colors used by various end-product and motor manufacturers. Repair people seldom if ever work on items that have been dismantled to the point that internal wire connections need to be determined. They may decline to work on such items if they encounter them.

It is probably not possible to use motor theory to confidently determine the connections of a motor like this. Careful testing with good instruments and a load would reveal which connection results in the most efficient operation.