Pretty much agree with Larisa. Looks like very mixed genetics, cross pollination. No way to tell the variety unless you have seed packets, or wherever you got the seed told you what. Lots of different varieties look similar.
The white looks like a flour dent, just a guess. Kernels should be fairly soft if so.
The purple is also a dent.
The yellow is clearly a flint. This is the only one that doesn't look like it cross pollinated much.
In years past I always saved it on the cob until spring when I chose which to save for seed. This year I had lots of weevils, so I shelled it all after drying and put it in the freezer to kill the bugs. Either way works fine depending on your circumstances.
The cobs are useful. I use a lot in the fireplace, and bury a lot in the garden. They break down quickly.
Moldy corn or cobs goes straight into the compost! Do not let it touch good corn. Some corn molds are poisonous, so I am very careful not to eat it and if I had animals I wouldn't
feed it to them either.