A very basic question but I can no longer see how to select what colour you want a track to be? This was very easy to find in Cubase 5 and appears to be tucked away now somewhere.
Ctrl-Click on the coloured area of the track header
(if it’s like cubase 8…)
then click on the color tool or the color menu. If you select “Project Colors”, then the Options button, you can add custom colors, which is very nice. (Slight hue/tone changes for related instruments keeps them distinct but not too much so.)