I get those. In my circle of friends, I have confirmed about ten or so others that have been seeing them.
They are usually bright silvery white for me, but sometimes black, but rarely a colour, but others get coloured ones more often than me. Anyway they are daily phenomenon and sometimes open up a bit to reveal a scene, or I get a download of information, or they appear as a confirmation to a thought.
The best explanation I have heard about what they are, are from channeled sources. As your energy rises, your holographic sphere is not as dense. This allows the beginnings of energy producing beings to interact with you for short periods of time. This reality, our general tonal of the times is very solid, but as our personal veil thins this allows for interaction with energy beings. I have heard them being called fairies and ET's of one kind or another by channels. My wife also sees them but she considers them a medical condition lol.
I used to tell them to bugger off and leave me alone , when they first started up about ten years ago, but now they are kinda neat to have around.