What can cause yoy to see like a swirly colored finger in your vision?

Floater: A vitreous floater, a change in the fluid in the back of your eye. These are a nuisance but gradually will become of no consequence to you. If you have any flashing lights or floaters persist then you should have an eye exam.

Usually a migraine: The most common cause of seeing colored lights in your vision is a form of migraine. The most typical form lasts for about 10-15 minutes and is then followed by a headache. However a headache is not always present. You should see your eye doctor, however, because what you describe could also be caused by a retinal problem which would need attention.