RM8 seems to be going in a loop when I add some people especially spouses so I get multiples of the same person.
Also, when you do “manual merges” you lose color coding. Color coding may be disappearing other times but I have not seen a pattern yet. But, merging definitely kills the color code.
Manual merge retains color coding for me. However, it retains the color coding of the primary person, not of the duplicate person. It’s hard to see how else it could work.
The duplicate person is being merged out of existence. Any data in the duplicate person that doesn’t exist in the primary person or that doesn’t match the primary person is kept in the primary person. But there is no way to retain two colors in the primary person because a person can only have one color.
If you don’t like the color that’s going to be kept, you can swap the two people before the merge is final.