increase the number of colors

[napo]

I have a gtfs with the many bus lines, therefore when I transform it to geojson, the color takes the value null.
How can I assign additional colors?

[mattnovelli]

Could you link to the GTFS?

[patrickbr]

I am not sure I understand your problem correctly - does the original input GTFS have any route colors? If not, you can always use random colors by adding the --random-colors flag to the transitmap tool.