Pls help me understand transformer

I studied this stuff in school 20 years ago. That makes me a newbie. My transformer has output as follows:
RedA + RedB= 48V
RedA + Black= 24V
RedB + Black =24V
WhiteA + Yellow =16V
WhiteB + Yellow =16V
WhiteA + WhiteB =32V
I tried other combinations and got different voltages, these were the obvious patterns.
I would like to use this power supply for bipolar 18V, 48V for phantom power, 5V and if I am fortunate, bipolar 15V for other ICs.
First I would like to understand the trans, then please suggest next step.
Thank you
 
You have a dual-secondary transformer, or at least dual-voltage secondary.

red/black/red is 24V-0V-24V or 48V with a center tap
yellow/white/yellow is 16V-0V-16V or 32V center tapped.

red is relative to black and to the other red. You can use either set of wires to use the voltage on them. Note that if you use the red-red voltage it will be only positive; if you use the red-black voltages it can be positive or negative or both. Similarly the yellow/whites.

Rectified, the DC voltage can be either 0.707 or (more usually) 1.414 times the voltage AC off the transformer. This tranformer seems suitable for any of the voltages you mentioned, if a voltage regulator is used.