No swatches showing for any panels
When I open up a file using the open with option inside of Windows explorer, my swatches are always empty no matter what panel I'm using. Colors panel, etc. The only way it doesn't seem to have this bug is if I'm inside of Adobe Illustrator and I open a file from inside of the program. This is very inconvenient.
This is working as expected. You have opened a png file and since a png file will not have Illustrator swatches it does not show up.
If you create a new Illustrator file will then see Illustrator swatches. Once you have created a new Illustrator file you can place the png file inside it.