They've been groomed for generations, yes. But they've not been stabilized. When i talk about the variety of tomato colors/tastes, this is something natural that will happen over a few generations in your garden.
Plants will often borrow taste from other surrounding plants, as for color i have no clue what triggers them to change, but i've seen with my own eyes after a few years, new generations of vegetables starting to change colors (not uniformly across the entire garden). This of course is not possible with trees (eg. apples/oranges) as you would need to wait several generations of trees (that's a long time), nor is it possible when you plant seeds from the supermarket every year to replace last year's plants, as the commercial seeds are almost bit-by-bit copies of one another and will yield the same tasteless tomatoes bypassing the natural circle of evolution to your local environment.
If you can, i strongly encourage to go talk to local farmers and borrow a few seeds. There's some amazing stuff out there which you won't find in commercial gardening shops. At least that's the case here in France, where the government for many years made it illegal/criminal to share or sell "peasant crops" (which a judge ruled is legal only a few years back).
