Just curious... I started with Eyetalian bees and they swarmed several times. Now my bees are significantly darker. I'm wondering what the mix might likely bee. Does the dark color follow any particular breed line?
If your bees have swarmed several times, then your Italian Queen isn't in the colony anymore, her daugther is, assuming your italian queen was mated prior to you installing the hive, then genetics were intact, your virgin queens now laying eggs for you, could have and would have bred with whatever could catch her whether your Italian drones or caucasians or old german bees( not alot of them anymore ).
The italian honey bee comes in a variety of color from very yellow (red heads) to almost black depending on the genetics that controls color. Several 'races' of bees are dark to very dark with some small distinction made based on the color bands on the workers abdomen being described as shades of gray or brown.