Memory color option

It would be nice to have memory color option in color picker.
For instance, a person wants to match his color (on the rigth) with a given color (on the left).
Let us say a person wants to memory left color, then the color picker shows `M+` button to do it.
When the `M+` pressed the color is referenced in memory.

Attachment 102444

Then the person samples a color on the right side (a yellowish one).
Now the color picker shows both colors - a reference color (written in the previous step) with black outline and a new color with white outline. Note, the button we pressed before has been changed to `M-` to clean a color from memory.

Attachment 102445

That way it is clear `how far` is new color from a reference color.