Just to get the terminology straight, flint corn has hard, glassy, high-protein kernels that are best for polenta, cornmeal, and wet-batter cornbread. Popcorn is a specialized type of flint corn and makes great cornmeal as well. Flint corn is the traditional corn of the north, and was grown in New England by First Nations peoples long before European settlement. Flour corn has kernels that are mostly soft, crumbly starch. This crushes to a fine powder that can be used in biscuits, breads, cake, and cookies as well as cornbread. It grows primarily in the southern tier of the country, and was perfected by the Pueblo peoples in the Southwest. Dent corn has a hard flinty outer shell and and soft floury interior--when it dries, the floury part shrinks, making a dent in the top of the kernel. Traditional dent corns were widespread over the south and Midwest. Modern commodity corns are primarily dent types, but some old heritage varieties survive, and
should be cherished. Southern Exposure Seed Exchange stewards several of them. Sweet corn is an oddity--a grain that is eaten when at the unripe green stage as a vegetable. Ancient
Native American breeders discovered and selected for the genes that make corn sweet instead of starchy. Modern breeding and hybridization has produced supermarket varieties that are for me, almost too sweet to eat. But heritage sweet corns are still available, and a few public-spirited modern breeders have continued to produce and improve open=pollinated (non-hybrid) sweet corns. "Glass Gem" is a multi-colored flint corn.
As with potatoes, each color has a slightly different flavor, and they are better for different purposes. And yes, the white is mildest. Yellow corn was not traditionally popular in the South for cornbread and fritters, especially on the coast, because the flavor of yellow corn conflicts with the flavor of fish. Thus the traditional white corns, for cornbread, all the way up into New England with Narragansett White.
Carol Deppe has done a lot of work with this. See her book The Resilient Gardener. She took
landrace multi-color corns, which she considered to have a muddy flavor from the conflicting colors, and separated them out into one-or-two-color lines for specific flavors. Thus the white and cream lines are for
pancakes, cookies, biscuits, and cakes. The yellow and gold for cornbread. The red for parching, gravy, polenta, and flavorful cornbread. The brown and maroon for gravy. And so on. Even though a variety like Magic Manna or Cascade Ruby-Gold has more than one color, each ear is all one color. So from one planting of Magic Manna you can get entire ears in each color, ready to use for separate purposes.
https://www.quailseeds.com/store/p397/Magic_Manna_Flour_Corn.html
Other high-nutrient corns like Floriani, Abenaki, and Wapsie Valley are a mix of just the yellow and red colors, which makes a very buttery, warm-flavored cornbread or polenta, without the admixture or blue, green, white, and brown kernels that muddy the flavor, but with the red and yellow pigments that add nutrients like carotene etc. These tend to be the cornmeals and polentas that win taste tests. They are not so bland as the white corns, (which shine in recipes where the flour is not supposed to add a separate flavor.) They are also not so tannic and strong-flavored as the darker corns, which are best suited to recipes that feature them, like blue cornmeal, posole,, parched corn, etc.
The highest-yielding and most versatile of these that I know of is Wapsie Valley Dent, which was bred by a farmer in the 1970's by combining many open-pollinated and Native American corns which were already becoming hard to get and disappearing. It is a large, easy-to-grow corn with outstanding flavor and high yields--combining the best traits of many traditional ancestors.https://www.quailseeds.com/store/p396/Wapsie_Valley_Dent_Corn.html It can be used for both flour and polenta. Bloody Butcher is a red corn, similar but less adaptable to areas outside the South. Floriani is a polenta corn all red, no yellow, and no flour, just polenta.
https://www.southernexposure.com/products/floriani-red-flint-flint-corn/
Dave Christensen bred the ground-breaking Painted Mountain flour corn in Northern Montana to be the most hardy and short-season-adapted flour corn available. (It is multi-colored, and Carol Deppe's Magic Manna is a descendant with single-color ears.) He now has a corn that is dark red, to have the highest nutrition as well as all the hardiness and low-input adaptability. I believe that he crossed in some Mexican morado corns for high nutrient values.
Alan Kapular did the same sort of thing with his sweet corn variety, Double Red. The late Jonathan Spero crossed modern sweet corns with ancient Anasazi corn to produce a sweet corn with multicolored ears called Festivity. If you are interested in nutrition, in modern
landrace plants, or in non-hybrid corns, it is well worth growing.
https://www.quailseeds.com/store/p485/Festivity_Sweet_Corn.html
If you are interested in corn history, genetics, cookery, and agriculture, you might request the book Beautiful Corn from your library. It is written by a farmer in the PNW and I believe it started as a newsletter to his CSA families but turned into a book all about corn. Both his book and Carol Deppe's are great introductions to the complex and unique world of corn and corn genetics. Corn as we know it is almost entirely the creation of ancient Native American farmers, and is arguably the greatest achievement in plant breeding ever.