I’m new to using expression maps. But I don’t understand how or why the color is implemented. Once set up and in the key editor, all the articulation tracks are light blue.
The one tutorial I saw, they guy gave a comprehensive presentation, but didn’t know how color was implemented either. 
I’m not really sure I understand what you are asking, but in the key editor you can choose to color the notes by sound slot. That way you can see each articulation change in a different color. Is that what you meant?
You understood just fine, and thank you.
I never messed with “color by sound slot” in the key editor, since color is almost always on velocity. Turning this to color by slot then matches the colors you have made in the expression map.
You are welcome! Having notes colored by articulation helps me a lot in the key editor.
Is it possible therefore to change the name of the colours from color 1 etc to something more intuative like “Short”, “Long” “Tenuto” etc