Aileen and rhizo, thanks for responding....I don't have a pic yet, but it seems they are opening better now and I have decided they might have been experiencing some shock at first, although there should have been no reason for that. Maybe the yellow ones are a bit more sensitive than others. thanks anyway!

Single carrot plants with multiple roots is called 'forking'. It happens from some form of damage to the main root; it usually happens in rocky or heavy soils, or you could have Carrot Rust Fly (CRF), or you added excessive nitrogen not long before planting. But since you had a few last year and a lot this year, and you planted in the same place, I vote for CRF. If you have CRF, there should have been some dark spots in the carrot roots, too, as the larvae tunnel into the roots and dump their manure (called frass). I have become something of an 'expert' on CRF. 8-( The two most important pieces of info that I received about CRF is that they remain in the soil, so you must move your carrot bed, and that they fly close to the ground, usually a foot or less. They must be practically invisible, because I've never noticed them, and I've lost entire crops to them. Because they fly low, you need to 'fence' them out. Move to a bed where you haven't grown root crops in the last year or two, and pound some stakes in the corners. Then wrap the bed with some clear kitchen plastic wrap (dollar store type will do fine). This fence must be about 18" tall, and sealed at the bottom so they can't crawl in (cover end of plastic with soil). Be careful with your watering, as the plastic can prevent sprinkler spray from getting near the sides. If you can spare the bed you used this past season, solarize it next summer to kill the existing CRF (and any nematodes that might be in there, too): Water the soil very well (dig down 6" to make sure you got it wet that far down), then cover the bed with clear plastic and seal the edges by covering with soil. Let the summer heat steam-bake the bed for 3-6 wks. If you have to fence it off to keep kids and dogs from puncturing the plastic, do it. THIS DOES NOT WORK WITH DRY SOIL! And it doesn't work very well in the shade, either. Sue

Have the plants checked for verticillium (or other) wilts if you are pretty certain it is not environmental or pests. Most areas have a plant disease clinic to which you can send your samples for testing. In the meantime, practice the highest level of sanitation: keep your tools sharp and clean, and disinfect pruners (and other tools) between plants; don't work on the plants when they are wet; etc.

Weather conditions may definitely affect bloom color. OTOH, it is possible that you have a sport. You could tag that cane, and watch to see what later blooms look like.