"I buy organic sugar for my own use. It is not turbdinado or any other version of semi-refined sugar, just from organic cane and not bleached pure white."
White sucrose is not bleached. Bleaching is a chemical process where colored materials are oxidized and thus made colorless. No such process is performed during sugar refinement. Rather, sugar is refined by simple recrystallization. Recrystallization is one of the two oldest methods of purifying chemicals. The other old option to purify is distillation if the substance happens to be stable at its boiling temperature.
Raw juice regardless if it comes from sugar cane, sugar beets, maple trees, etc has a variety of impurities, dirt, fungi, bacteria, plant parts, bugs parts and dissolved minerals in it. Probably the occasional ground up rabbit also. It also only has a low concentration of sugar so would not have any shelf life. Generally the first process is to simply boil off much of the water. Then the concentrated solution is filtered to remove insolubles. After further concentration the solution is cooled and raw sucrose crystallizes. This raw sucrose will have various color agents in it, decomposition products produced during the boiling process as well as some impurities just along for the ride. Feeding this to bees, particularly for winter food, is a great way to kill a hive due to all the indigestible solids present such as polysaccharides and sucrose degradation products that can be toxic to bees even thou they are not particularly toxic to most people.
This raw sucrose is redissolved in water, often treated with charcoal to absorb colored and non colored impurities, reconcentrated by boiling, and recrystallized by cooling the resulting solution. If all has gone well you have white sucrose at that point.
The rule of thumb for what is safe to feed your bees is if the sucrose is snow white and labeled either cane or beet sugar and dissolves to make a near water clear and colorless solution it is safe. Anything else may, or may not be safe. If it is safe it is because you got lucky. If it is not safe it will harm your bees to a greater or lesser extent. There are no nutrients in colored sugars of the slightest benefit to bees. The sucrose that bees collect from plants is not loaded up with crap that is the inevitable result of boiling sucrose solutions in order to isolate white sugar. Why not feed them what they eat in nature rather then some degraded mess? Either feed white sugar or feed high fructose corn syrup as those are the two excellent mimics of nectar.