https://docs.unity3d.com/Packages/com.unity.2d.animation@2.2/manual/SLASwap.html
details how to color swap between the colors of the 2 different palettes of the imported images.
What would be very neat to have is the ability to import just a grayscale sprite, and be able to determine the color of a certain gray area directly in unity. It would be nice to be able to save the colors of a certain gray area in a kind of a preset, and maybe even save a colored sprite as a prefab variant.
It seems very tedious redundant to create copies of differently colored sprites within imaging programs, with the inability to quickly modify a color of a certain part down the line.