welcome to the macprovideo forums!
By default the track's colors are set to blue (audio) and green (software instrument).
You can turn on/off the color bar for track headers by right-clicking on a track header and choosing:
"Configure Track Header".
But, it won't automatically assign different colours to newly created tracks unfortunately...
One way, is to create a template. Let's say you often work with 16 audio tracks. Create a new project with x number of audio tracks and manually assign a new color to each of them.
Save the project as a template: File > Save as template...
Hope that helps