Not sure why you want to know the color label. The purpose of color labeling is for easy filtering, e.g., you want to see only the red images, or only the yellow images, or just the red + yellow but nothing else.
Can you give a more specific example of why you need to know what the actual color is and how it would assist in your workflow? Maybe there's another way to accomplish what you're trying to do ...
Let's say I have a headshot shoot. The client selects his photos, and they get flagged.
I want to keep some for me, to post them on my website. As the flags are already used for the client, I need to use a label.
A simple red dot would do, as I will choose far less images than the client. The client might pick between 7 and 30, I will only pick 1 or 2, 3 maximum. But I need to see the photos that I picked when I look at the grid view.
Contenders could get another color, blue for example.
If I decide to make a hard copy of one of them: third color.
Imagine you use all six available colors. Your grid would be speckled as if you were shooting a job for easter bunny.
A color dot would be much less intrusive into one's color perception of the image than a colored frame.
Have you seen paintings sold in a gallery? They get a tiny red dot when they are sold. It's tiny, easily discernible if you are looking for it, but does not disturb your looking at the image.
Color labelling is great, but needs refinement, more choices for personal preferences.
I saw, that you can switch off the colored frames. Then you do not know, when you look, comparing, at the grid, which ones you already chose.