First off you need to be viewing the color chips with a neutral color to surround the chip in the book. The white surround in the book throws your eyes WAY off.
Second you need to look at the chips in different light as some colors have a gross difference if you are in direct sunlight or in shade.
The lombard blue is a great example. In the sun it looks very blue, but in the shade it is not far off from a black (if it is done properly).
I have a great, but small bit of original Lombard blue I found on my door. It was behind some felt and did not have much exposure to air. When I did my best to compare the colors to what the paint handbook had in the chips they were real close. A major admission, I am far from trained in knowing colors and matching. Knowing colors is something few are truly good at and you must be practiced.
Now the era formula for Lombard (hopefully I am remembering right it has been years) was 2 blues, a green and a black. Yes, lombard blue will have a slight green undertone if you figure out how to look at it. The current PPG Concept formula has the 2 blues, green and black, but they ruin it with a dash of white. I have been kicking myself for letting them add in the white as that lightened it up.
So do not trust the mix that the dealer will give you as being correct.
I called PPG and they told me what the original tint formula was back in the 30's and they told me the formula they use today. I did not have to lie about who I was, they were very forward in talking with me.
Getting the color right is not an easy job and not something a lot of people know enough to figure it out on the first try. I had some great help and I barely got something that is not correct, but close enough for my budget. Paint is not cheap!!
Keep in mind I bought paint online from company that is well known. They claimed they could get it right including the muddiness found in the less refined tints of the 30's. They did not get the color right and something was wrong with the tints causing white speckles.
Now you have my experience with paint color. Hope it helps a bit.